US3710390A - Monopulse switching system - Google Patents

Monopulse switching system Download PDF

Info

Publication number
US3710390A
US3710390A US00658915A US65891557A US3710390A US 3710390 A US3710390 A US 3710390A US 00658915 A US00658915 A US 00658915A US 65891557 A US65891557 A US 65891557A US 3710390 A US3710390 A US 3710390A
Authority
US
United States
Prior art keywords
signal
azimuth
elevation
microwave
phase inverter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00658915A
Inventor
D Kreinheder
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Co
Original Assignee
Hughes Aircraft Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes Aircraft Co filed Critical Hughes Aircraft Co
Priority to US00658915A priority Critical patent/US3710390A/en
Application granted granted Critical
Publication of US3710390A publication Critical patent/US3710390A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/66—Radar-tracking systems; Analogous systems
    • G01S13/68—Radar-tracking systems; Analogous systems for angle tracking only

Definitions

  • An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the comers of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said Jan.
  • radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling and said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing said reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase in
  • SHEET 2 OF 2 92 flax/.4454 v MONOPULSE SWITCHING SYSTEM This invention relates to tracking systems, and more particularly, to an electronic lobe switching means for and a method of intercoupling a simultaneous lobing antenna and a single channel microwave receiver to provide a wave energy tracking system.
  • Simultaneous lobing systems of the prior art for tracking a target utilize a single stationary wave energy beam for illuminating the target which, upon reflection, provides an echo signal from which the desired position information of the target may be abstracted.
  • the antenna of such a system which is designated as a simultaneous lobing antenna includes four symmetrically spaced radiator elements which are equally excited by the transmitter of the system to provide the illuminating beam. These four radiator elements are also coupled to the receivers of the system and are excited by the echo signal to provide information of the target location.
  • the four signals developed by the four radiators are mixed in a phase and amplitude sensitive hybrid junction means, usually comprising three or four hybrid junctions to develop simultaneous lobing antenna output signals designated as the sum signal, azimuth signal, and the eleyation signal.
  • the relative amplitudes and phases of the waves excited in the radiators by the echo signal are proportional to the angular position of the target in a plane perpendicular to the axis of symmetry of the four radiator elements.
  • two space quadrature difference signals designated herein as the azimuth signal and the elevation signal may be developed which give the angular position of the target in terms of rectangular coordinates.
  • this position information is utilized to maintain the symmetry axis in coincidence with the line of sight in much the same manner as used in conical scan tracking techniques by using a feedback system including a torquer system to move and constantly maintain the antenna axis in coincidence with the line of sight.
  • a monopulse system which most commonly employs a simultaneous lobing antenna and which, for the purpose of this specification, is defined as a system capable of providing complete position 'data upon transmission of a single pulse
  • the three output signals received from the simultaneous lobing antenna are fed to three different microwave receivers for demodulation.
  • the output of each receiver is combined and its phase detected to obtain complete position information.
  • the desirable major characteristics of a tracking system are complete absence of moving parts in the antenna, electrical simplicity of the receiver system and ability to provide complete positional target information in a short time interval.
  • the conventional monopulse tracking system hereabove described requires three microwave receivers which introduce great electrical complexity and require additional space in an otherwise desirable tracking system.
  • a conventional simultaneous lobing antenna which provides three output signals respectively designated as sum, azimuth, and elevation output signals.
  • the output signals themselves are combined to provide a single microwave error signal.
  • the intermixing of the signals is undertaken in much the same way as a carrier is modulated by information. More particularly, the sum signal furnishes a convenient pulsed carrier and the azimuth signal and the elevation signal are selectively added to or subtracted from the sum signal. This selective combination takes place in accordance with a predetermined scheme such as may be provided by a pro gramming unit.
  • the sum signal, after having impressed upon it the azimuth and the elevation signals, is designated as the microwave error signal.
  • Them microwave error signal which includes complete position. information of the target is then demodulated in a. single receiver.
  • a reference signal from the programming unit is then utilized for detecting the phase of the demodulated microwave error signal in accordance with the prior modulation. Upon phase detecting, error voltages representative of the azimuth and the elevation of the target are obtained.
  • FIG. l is a schematic block diagram of the wave energy tracking system in accordance with this invention.
  • FIG. 2 is an illustrative diagram showing the geomet rical position of a target with respect to the simultaneous lobing planes
  • FIG. 3 is a schematic block diagram of an embodiment of the electronic reference generator included in the system of FIG. 1;
  • FIG. 4 is an illustrative diagram showing the correspondence between designated signals on a time-amplitude basis.
  • the simultaneous lobing antenna 10 includes four radiators ll, l2, l3 and 14 which are symmetrically positioned within a parabolic reflector schematically indicated by a dotted line 16 and usually occupy the corners of a square.
  • the simultaneous lobing antenna 10 also includes a hybrid junction means made up of three hybrid junctions 18, 20and 22 and a T- junction 24. It is self evident to those skilled in the art that a fourth hybrid junction may be substituted for the T-junction wherein the difference branch arm is terminated in a matched load.
  • the pair of radiators 11 and 12 are directly coupled to the symmetry branch arms 26 and 28 of hybrid junction 18 and the pair of radiators 13 and 14 are coupled to the symmetry branch arms 30 and 32 of hybrid junction 20.
  • the radiators 11 14 may be dipoles, waveguide horns, or slots.
  • the sum branch arm 34 of hybrid junction 18 and the sum branch arm 36 of hybrid junction 20 are each coupled to a different symmetry branch arm of hybrid junction 24.
  • the difference branch arm 38 of hybrid junction 18 and difference branch arm 40 of hybrid junction 20 are each coupled to a different terminal of the T-junction 24.
  • the hybrid junction means is adapted to provide vector addition and subtraction of the wave energy excited by the radiators between all radiators taken in pairs.
  • the simultaneous lobing antenna 10 has three output terminals which are respectively designated as the sum output terminal 42, the azimuth output terminal 44 and the elevation output terminal 46 and which are respectively the sum and difference branch arm of hybrid junction 22 and the leg of the T-junction 24.
  • the azimuth terminal 44 and the elevation terminal 46 are both coupled to a two-channel microwave switch 50, the operation of which is controlled by a first control signal.
  • the control signal is an electrical signal whose frequency is in the range of IO to 10,000 cycles per second.
  • the switch 50 operates like a single-pole, double-throw switch and in accordance with the control signal impresses either the signal from the elevation terminal 46 or the signal from the azimuth terminal 44, but not both, to the output terminal 52.
  • microwave switches are well known in the art.
  • a ferrite microwave switch is described in detail in, High Speed Ferrite Microwave Switches, by George S. Uebele, published in the IRE Convention Record, 1957 National Convention, Part 1, Pages 227-234. v
  • the output terminal 52 of the switch 50 is coupled to a phase inverter 54, the operation of which is likewise controlled by a second control signal.
  • This second control signal is similar in character to the first control signal but has a frequency which differs therefrom as will be explained in detail below.
  • the function of the phase inverter 54 is to permit propagation of the signal from the switch 52 therethrough either, with or without subjecting the signal to a 180 phase shift as determined by the second control signal.
  • the output terminal 56 of the phase inverter 54 is coupled to the sum terminal 42 by means of an intercoupling network 60 which may be a vestigial Y-junction well known to those skilled in the art.
  • a microwave gas discharge device 58 which may be a conventional TR tube is provided in the leg of the Y-junction 60 which upon being fired will prevent microwave energy traversing junction 60 from passing to the phase inverter 54.
  • An electronic reference generator 64 which provides the first and the second control signal is coupled to the switch 50 and the phase inverter 52 as shown.
  • the electronic reference generator also provides a reference signal which, as will be explained later, is used in the process of phase detecting the error voltages.
  • the combination of the two-channel switch 50, the phase inverter 54, the intercoupling network 60 and the electronic reference generator 64 is referred to as the switching circuit which intercouples the simultaneous lobing antenna 10 with a microwave transceiver 66.
  • the transceiver 66 is a conventional microwave receiver and transmitter combination such as is used with conical scan wave energy tracking systems.
  • the switching circuit has a single microwave output terminal 62 which is coupled to the receiver 66 and a single electrical output for a reference signal which is coupled to the phase detector portion of the receiver 66.
  • FIG. 2 shows the position of an assumed target 72 and its associated geometry when sighting along the symmetry axis 70 extending through the plane of the paper of the simultaneous lobing antenna 10.
  • the target 72 is located above the azimuth plane 74 and to the right of the elevation plane 76.
  • the azimuth error of the target is approximately twice as large as the elevation error.
  • the radiators which occupy positions on lines making a 45 degree angle with the two planes 74 and 76 are so spaced that both the azimuth signal and the elevation signal are positive.
  • the designation of a signal as positive denotes that the phase thereofis the same as the phase of the sum signal. In other words, the quadrant in which target 72 is located provides positive or in-phase error pulses for both the azimuth and the elevation signal.
  • the electronic reference generator 64 of FIG. 1 is shown in greater detail in FIG. 3 and includes as its basic component a master oscillator 80.
  • the oscillator 80 provides a sinusoidal output signal 82 which, as will be explained later on, is impressed on the receiver 66 for the purpose of phase detection.
  • the oscillator 80 is also coupled to an amplifier and limiter 84 which converts the sinusoidal output signal 82 into a square wave 86 having the fundamental frequency of the oscillator 80.
  • the square wave 86 is the second control signal and is applied to the phase inverter 54 of FIG; 1 to control the operation of the phase inverter 54.
  • the oscillator is also coupled to another amplifier and limiter 88 through a frequency doubler90.
  • the frequency doubler 90 doubles the frequency of the sinusoidal output signal 82 to provide sine wave 91.
  • the amplifier and limiter 88 converts the sine wave 91 into a second square wave 92 having a fundamental frequency of twice that of the fundamental frequency of the oscillator 80.
  • the square wave'92 is the first control signal and is impressed on the switch 50 of FIG. 1 to control the single-pole double-throw switch.
  • a transmitter incorporated in the receiver 66 supplies pulsed microwave energy commonly referred to as the main bang or the main transmitted pulse to output terminal 62 of the switching circuit of FIG. 1.
  • the main bang passes through the Y-junction 60 and fires the gas discharge device 58 thereby creating a short circuit at that coupling junction. If the gas discharge device is a conventional TR tube its location will be an integer number of half wavelengths from the junction point.
  • the main bang then passes to the sum branch arm 42 of hybrid junction 22 wherein it is equally divided into two portions and transmitted by the associated symmetry branch arms thereof to the sum branch 34 and 36 of hybrid junctions l8 and respectively.
  • Hybrid junctions 18 and 20 further divide the main bang into equal portions and deliver one quarter of the wave energy of the main bang to each of the radiators 11, 12, 13 and 14.
  • the radiators so excited illuminate the target by generating a single beam whose axis is coincident with the axis of symmetry of the system.
  • the radiators give rise to four separate beams but for the purpose of discussing the illumination of the target the four beams may be considered as a single illuminating beam.
  • FIG. 4 shows four successive main bang pulses, 100, 101, 102 and 103.
  • the target reflects a portion of the illuminated wave energy which reflected wave again excites the radiators 11, 12, 13 and 14. If the target is located at a point not lying on the symmetry axis of the antenna system such as the assumed target 72 in FIG. 2, the excitations of the individual radiators will be out of phase. In fact, this phase difference in the excitation of the individual radiators provides the positional information of the location ofthe target.
  • the wave energy excited by means of the radiators 11 and 12 within the symmetry branch arms of the hybrid junctions 18 are vectorially added and subtracted therewithin so that the sum terminal 34 and the difference terminal 38 provide the respective vector sum and the vector difference.
  • the wave energy excited by means of the radiators 13 and 14 within the symmetry branch arms of the hybrid junction 20 are vectorially added and subtracted therewithin so that the sum terminal 36 and the difference terminal 40 provide respectively the vector sum and the vector difference.
  • radiators 11 and 12 and radiators 13 and 14 are further vectorially added and subtracted in hybrid junction 22 from which is derived the vector sum of radiators 11 to 14 to provide the sum signal in sum terminal 42 and the vector difference providing the azimuth signal in azimuth terminal 44.
  • the T-junction 24 provides the sum of the phase difference between radiators 11 and 12 and radiators l3 and 14, which sum gives rise to the elevation signal in the elevation terminal 46.
  • FIG. 4 shows four consecutive pulses 104, 105, 106 and 107 of the sum signal.
  • the time displacement t between the pulse 100 of the main bang and the pulse 104 of the sum signal provides an indication of the range of the target, t being the time it takes the wave energy to travel twice the distance from the simultaneous lobin g antenna to the target.
  • the azimuth signal shown in FIG. 4 comprises the pulses 108, 109, 110 and 111.
  • the relative magnitude of the pulses is a direct indication of the azimuth angle of the target.
  • the elevation signal also shown in FIG. 4 is designated by pulses 112, 113, 114 and 115.
  • the relative amplitude of the elevation pulse 112 is approximately twice the amplitude of the azimuth pulses 108 which is an indication that the elevation angle is twice as great as the azimuth angle.
  • the above three signals namely the sum, azimuth and elevation signals are the output signals of the conventional simultaneous lobing antenna. Mixing of these signals is accomplished by the switching circuit of this invention which, by combining these signals, derives a single microwave signal.
  • the fundamental frequency of the master oscillator of the electronic reference generator of FIG. 3 is one-quarter of the pulse repetition rate of the trans mitter incorporated into transceiver 66 which originates the main bang. Hence, there are four main bang pulses to one cycle of the oscillator 80.
  • the microwave switch 50 of F IG. 1 is actuated by the control signal 92 of FIG. 3 having a frequency twice that of the oscillator. Since the switch is brought to the same position every second pulse, the switch will alternately pass an azimuth signal pulse and an elevation signal pulse to the phase inverter. This is illustrated diagrammatically in FIG. 4 where the output from the switch consists of azimuth signal pulse 108 followed by elevation signal pulse 113 which again is followed by azimuth signal pulse 110 and elevation signal pulse 115.
  • the pulse inverter 54 of FIG. 1 is actuated by the square wave signal 86 of FIG. 3 which has the same frequency as the oscillator and which will actuate the phase shifter twice during each oscillator cycle. In other words, the phase inverter 54 will let two pulse signals pass through without changing the phase and thereafter invert the phase of the next two pulses. In accordance with the designation of the term positive or in-phase, the inverted phase pulse will be negative. This can be seen diagrammatically in FIG. 4 where pulse 108 and pulse 113 from the switch 50 are permitted to pass freely through the phase inverter whereas pulse 110' and 115' have suffered a 180 phase shift with respect to the pulses from the switch 50.
  • pulse 116 is a combination or addition of pulse 104 and 108
  • pulse 117 is a combination of pulse 105 and 113
  • pulse 118 is a combination of pulse 106 and 110
  • pulse 119 is a combination of pulse 107 and l 15'.
  • the pulses l 16, 1 17, 118 and 119 provide the single microwave error signal having; an envelope 120 which is the error envelope from which error voltages representative of the azimuth and elevation may be obtained by conventional demodulation taking place within the transceiver 66.
  • the microwave error signal of FIG. 4 whose envelope 120 has the same frequency as the reference signal 82 of FIG. 3 is applied to the standard microwave receiver incorporated into transceiver 66 which has a mixing stage, an IF stage, and which demodulates the microwave error signal to abstract therefrom the envelope 120. Thereafter, the envelope 120 is phase detected by means of the reference signal 82 by standard conical scan tracking methods as are well known to those skilled in the art.
  • the switching means used in deriving the microwave error signal employs a microwave switch and a microwave phase inverter both of which are only required to handle very small amounts of wave energy power and which therefore can be very efficiently operated.
  • the advantages which the wave energy tracking system of this invention provide are the use of a simultaneous lobing antenna system having no moving parts and therefore greater mechanical simplicity and a single microwave receiver as used in conical scanning techniques with a resultant saving of weight and space.
  • an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal and a reference signal and adapted to develop corresponding demodulated error voltages therefrom,
  • said switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal
  • said switching circuit coupling said monopulse antenna to said receiver and comprising: a phase inverter; a microwave two-channel switch coupled to said phase inverter and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverte r being responsive to a second control signal to selectively impart a 180 phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal andthe selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
  • an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal'and a 'reference'signal and adapted todevelop corresponding demodulated error voltages therefrom, and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse I antenna to said receiver and comprising: a phase inverter; an electronic reference generator adapted to develop said reference signal, a first control signal and elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal to sequentially impart a 180 degree phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal and the sequentially phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal there
  • An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and hybrid junction means having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of microwave signal received from said target, said hybrid junction means being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit coupling said simultaneous lobing antenna to said receiver, said switching circuit including a phase inverter, an electronic reference generator adapted to develop said reference signal, a first control signal and a second control signal, a microwave two
  • An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each'of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter and adder means, said switch being coupled to said phase inverter and responsive to a first
  • An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing an tenna including four symmetrically positioned radiators defining the comers of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing a reference signal

Abstract

6. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling and said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing said reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal for sequentially introducing a 180* phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.

Description

United States Patent [191 Kreinheder MONOPULSE SWITCHING SYSTEM [75] Inventor: Donald E. Kreinheder, Los Angeles, Calif.
[73] Assignee: Hughes Aircraft Company, Culver City, Calif.
[22 Filed: May 1, 1957 [21] Appl. No.: 658,915
Primary Examiner-Malcolm F. Hubler Attorney-James K. Haskell and Earnest F. Oberhcim EXEMPLARY CLAIM 6. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the comers of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said Jan. 9, 1973 radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling and said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing said reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal for sequentially introducing a 180 phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
8 Claims, 4 Drawing Figures /4 26 14/44 7512mm a Mae/0 54 A! 62 a Juana/r 66 Fr 3! 22 5a 2! 0 l/ya/e/o 54 a 30 Jm ar/o/v Zia/(1416 4g fl df' 44 Ara 4 764 X/VJl/a M Javarlo 42/4/021/ 7210/44/44 52 4 36 U 7 za 4%] Acme Var/a! i lazy/Wow RIM/#44 5 PJI/Adz/a ii/zzaraw r64 arr/0,40: 10215414;
SHEET 1 BF 2 law/- PATENTEDJAH 9 ma 3.710.390
SHEET 2 OF 2 92 flax/.4454 v MONOPULSE SWITCHING SYSTEM This invention relates to tracking systems, and more particularly, to an electronic lobe switching means for and a method of intercoupling a simultaneous lobing antenna and a single channel microwave receiver to provide a wave energy tracking system.
Simultaneous lobing systems of the prior art for tracking a target utilize a single stationary wave energy beam for illuminating the target which, upon reflection, provides an echo signal from which the desired position information of the target may be abstracted. The antenna of such a system, which is designated as a simultaneous lobing antenna includes four symmetrically spaced radiator elements which are equally excited by the transmitter of the system to provide the illuminating beam. These four radiator elements are also coupled to the receivers of the system and are excited by the echo signal to provide information of the target location. The four signals developed by the four radiators are mixed in a phase and amplitude sensitive hybrid junction means, usually comprising three or four hybrid junctions to develop simultaneous lobing antenna output signals designated as the sum signal, azimuth signal, and the eleyation signal.
The relative amplitudes and phases of the waves excited in the radiators by the echo signal are proportional to the angular position of the target in a plane perpendicular to the axis of symmetry of the four radiator elements. By comparing the relative amplitudes and phases of the waves in the four radiators with one another, two space quadrature difference signals designated herein as the azimuth signal and the elevation signal may be developed which give the angular position of the target in terms of rectangular coordinates.
In practice, this position information is utilized to maintain the symmetry axis in coincidence with the line of sight in much the same manner as used in conical scan tracking techniques by using a feedback system including a torquer system to move and constantly maintain the antenna axis in coincidence with the line of sight.
In a monopulse system, which most commonly employs a simultaneous lobing antenna and which, for the purpose of this specification, is defined as a system capable of providing complete position 'data upon transmission of a single pulse, the three output signals received from the simultaneous lobing antenna are fed to three different microwave receivers for demodulation. The output of each receiver is combined and its phase detected to obtain complete position information.
The desirable major characteristics of a tracking system are complete absence of moving parts in the antenna, electrical simplicity of the receiver system and ability to provide complete positional target information in a short time interval. The conventional monopulse tracking system hereabove described requires three microwave receivers which introduce great electrical complexity and require additional space in an otherwise desirable tracking system.
It is therefore an object of this invention to provide a wave energy tracking system incorporating the advantages of the monopulse tracking system whileat the same time requiring but a single microwave receiver.
It is a further object of this invention to provide a wave energy tracking system which provides complete position information of a target by means of four consecutive pulses and which requires but a single microwave receiver.
It is a still further object of this invention to provide a new method for tracking targets in space incorporating simultaneous lobing antenna techniques and electroni cally intermixing the antenna output signals to develop a single microwave error signal.
It is a still further object of this invention to provide a method of tracking targets in space which is simple and reliable in operations and which substantially decreases the complexity attendant in conventional monopulse tracking systems.
In accordance with one embodiment of this invention a conventional simultaneous lobing antenna is utilized which provides three output signals respectively designated as sum, azimuth, and elevation output signals. Instead of providing a microwave receiver for each of these output signals the output signals themselves are combined to provide a single microwave error signal. The intermixing of the signals is undertaken in much the same way as a carrier is modulated by information. More particularly, the sum signal furnishes a convenient pulsed carrier and the azimuth signal and the elevation signal are selectively added to or subtracted from the sum signal. This selective combination takes place in accordance with a predetermined scheme such as may be provided by a pro gramming unit.
The sum signal, after having impressed upon it the azimuth and the elevation signals, is designated as the microwave error signal. Them microwave error signal which includes complete position. information of the target is then demodulated in a. single receiver. A reference signal from the programming unit is then utilized for detecting the phase of the demodulated microwave error signal in accordance with the prior modulation. Upon phase detecting, error voltages representative of the azimuth and the elevation of the target are obtained.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which several embodiments. of the invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.
FIG. l is a schematic block diagram of the wave energy tracking system in accordance with this invention;
FIG. 2 is an illustrative diagram showing the geomet rical position of a target with respect to the simultaneous lobing planes;
FIG. 3 is a schematic block diagram of an embodiment of the electronic reference generator included in the system of FIG. 1; and
FIG. 4 is an illustrative diagram showing the correspondence between designated signals on a time-amplitude basis.
Referring now to the drawings wherein like reference characters designate like parts and particularly to FIG. 1 there is shown schematically a conventional simultaneous lobingantenna coupled to a switching circuit which switching circuit is an important factor of this invention. The simultaneous lobing antenna 10 includes four radiators ll, l2, l3 and 14 which are symmetrically positioned within a parabolic reflector schematically indicated by a dotted line 16 and usually occupy the corners of a square. The simultaneous lobing antenna 10 also includes a hybrid junction means made up of three hybrid junctions 18, 20and 22 and a T- junction 24. It is self evident to those skilled in the art that a fourth hybrid junction may be substituted for the T-junction wherein the difference branch arm is terminated in a matched load.
The pair of radiators 11 and 12 are directly coupled to the symmetry branch arms 26 and 28 of hybrid junction 18 and the pair of radiators 13 and 14 are coupled to the symmetry branch arms 30 and 32 of hybrid junction 20. The radiators 11 14 may be dipoles, waveguide horns, or slots. The sum branch arm 34 of hybrid junction 18 and the sum branch arm 36 of hybrid junction 20 are each coupled to a different symmetry branch arm of hybrid junction 24. The difference branch arm 38 of hybrid junction 18 and difference branch arm 40 of hybrid junction 20 are each coupled to a different terminal of the T-junction 24. In this manner, the hybrid junction means is adapted to provide vector addition and subtraction of the wave energy excited by the radiators between all radiators taken in pairs.
The simultaneous lobing antenna 10 has three output terminals which are respectively designated as the sum output terminal 42, the azimuth output terminal 44 and the elevation output terminal 46 and which are respectively the sum and difference branch arm of hybrid junction 22 and the leg of the T-junction 24.
The azimuth terminal 44 and the elevation terminal 46 are both coupled to a two-channel microwave switch 50, the operation of which is controlled by a first control signal. In contradistinction to microwave signals, the control signal is an electrical signal whose frequency is in the range of IO to 10,000 cycles per second. The switch 50 operates like a single-pole, double-throw switch and in accordance with the control signal impresses either the signal from the elevation terminal 46 or the signal from the azimuth terminal 44, but not both, to the output terminal 52. Such microwave switches are well known in the art. By way of example, a ferrite microwave switch is described in detail in, High Speed Ferrite Microwave Switches, by George S. Uebele, published in the IRE Convention Record, 1957 National Convention, Part 1, Pages 227-234. v
The output terminal 52 of the switch 50 is coupled to a phase inverter 54, the operation of which is likewise controlled by a second control signal. This second control signal is similar in character to the first control signal but has a frequency which differs therefrom as will be explained in detail below. The function of the phase inverter 54 is to permit propagation of the signal from the switch 52 therethrough either, with or without subjecting the signal to a 180 phase shift as determined by the second control signal.
The output terminal 56 of the phase inverter 54 is coupled to the sum terminal 42 by means of an intercoupling network 60 which may be a vestigial Y-junction well known to those skilled in the art. A microwave gas discharge device 58 which may be a conventional TR tube is provided in the leg of the Y-junction 60 which upon being fired will prevent microwave energy traversing junction 60 from passing to the phase inverter 54.
An electronic reference generator 64 which provides the first and the second control signal is coupled to the switch 50 and the phase inverter 52 as shown. The electronic reference generator also provides a reference signal which, as will be explained later, is used in the process of phase detecting the error voltages.
The combination of the two-channel switch 50, the phase inverter 54, the intercoupling network 60 and the electronic reference generator 64 is referred to as the switching circuit which intercouples the simultaneous lobing antenna 10 with a microwave transceiver 66. The transceiver 66 is a conventional microwave receiver and transmitter combination such as is used with conical scan wave energy tracking systems. The switching circuit has a single microwave output terminal 62 which is coupled to the receiver 66 and a single electrical output for a reference signal which is coupled to the phase detector portion of the receiver 66.
FIG. 2 shows the position of an assumed target 72 and its associated geometry when sighting along the symmetry axis 70 extending through the plane of the paper of the simultaneous lobing antenna 10. The target 72 is located above the azimuth plane 74 and to the right of the elevation plane 76. For the assumed target position the azimuth error of the target is approximately twice as large as the elevation error. It is further assumed that the radiators which occupy positions on lines making a 45 degree angle with the two planes 74 and 76 are so spaced that both the azimuth signal and the elevation signal are positive. The designation of a signal as positive denotes that the phase thereofis the same as the phase of the sum signal. In other words, the quadrant in which target 72 is located provides positive or in-phase error pulses for both the azimuth and the elevation signal.
The electronic reference generator 64 of FIG. 1 is shown in greater detail in FIG. 3 and includes as its basic component a master oscillator 80. The oscillator 80 provides a sinusoidal output signal 82 which, as will be explained later on, is impressed on the receiver 66 for the purpose of phase detection. The oscillator 80 is also coupled to an amplifier and limiter 84 which converts the sinusoidal output signal 82 into a square wave 86 having the fundamental frequency of the oscillator 80. The square wave 86 is the second control signal and is applied to the phase inverter 54 of FIG; 1 to control the operation of the phase inverter 54.
The oscillator is also coupled to another amplifier and limiter 88 through a frequency doubler90. The frequency doubler 90 doubles the frequency of the sinusoidal output signal 82 to provide sine wave 91. The amplifier and limiter 88 converts the sine wave 91 into a second square wave 92 having a fundamental frequency of twice that of the fundamental frequency of the oscillator 80. The square wave'92 is the first control signal and is impressed on the switch 50 of FIG. 1 to control the single-pole double-throw switch.
The operation of the wave energy tracking system of this invention will now be explained with the aid of FIG. 4. A transmitter incorporated in the receiver 66 supplies pulsed microwave energy commonly referred to as the main bang or the main transmitted pulse to output terminal 62 of the switching circuit of FIG. 1. The main bang passes through the Y-junction 60 and fires the gas discharge device 58 thereby creating a short circuit at that coupling junction. If the gas discharge device is a conventional TR tube its location will be an integer number of half wavelengths from the junction point. The main bang then passes to the sum branch arm 42 of hybrid junction 22 wherein it is equally divided into two portions and transmitted by the associated symmetry branch arms thereof to the sum branch 34 and 36 of hybrid junctions l8 and respectively. Hybrid junctions 18 and 20 further divide the main bang into equal portions and deliver one quarter of the wave energy of the main bang to each of the radiators 11, 12, 13 and 14. The radiators so excited illuminate the target by generating a single beam whose axis is coincident with the axis of symmetry of the system. Actually the radiators give rise to four separate beams but for the purpose of discussing the illumination of the target the four beams may be considered as a single illuminating beam. FIG. 4 shows four successive main bang pulses, 100, 101, 102 and 103.
The target reflects a portion of the illuminated wave energy which reflected wave again excites the radiators 11, 12, 13 and 14. If the target is located at a point not lying on the symmetry axis of the antenna system such as the assumed target 72 in FIG. 2, the excitations of the individual radiators will be out of phase. In fact, this phase difference in the excitation of the individual radiators provides the positional information of the location ofthe target.
The wave energy excited by means of the radiators 11 and 12 within the symmetry branch arms of the hybrid junctions 18 are vectorially added and subtracted therewithin so that the sum terminal 34 and the difference terminal 38 provide the respective vector sum and the vector difference. Similarly, the wave energy excited by means of the radiators 13 and 14 within the symmetry branch arms of the hybrid junction 20 are vectorially added and subtracted therewithin so that the sum terminal 36 and the difference terminal 40 provide respectively the vector sum and the vector difference.
The vector sums, respectively, of radiators 11 and 12 and radiators 13 and 14 are further vectorially added and subtracted in hybrid junction 22 from which is derived the vector sum of radiators 11 to 14 to provide the sum signal in sum terminal 42 and the vector difference providing the azimuth signal in azimuth terminal 44. In a similar fashion, the T-junction 24 provides the sum of the phase difference between radiators 11 and 12 and radiators l3 and 14, which sum gives rise to the elevation signal in the elevation terminal 46.
FIG. 4 shows four consecutive pulses 104, 105, 106 and 107 of the sum signal. The time displacement t between the pulse 100 of the main bang and the pulse 104 of the sum signal provides an indication of the range of the target, t being the time it takes the wave energy to travel twice the distance from the simultaneous lobin g antenna to the target.
The azimuth signal shown in FIG. 4 comprises the pulses 108, 109, 110 and 111. The relative magnitude of the pulses is a direct indication of the azimuth angle of the target. The elevation signal also shown in FIG. 4 is designated by pulses 112, 113, 114 and 115. The relative amplitude of the elevation pulse 112 is approximately twice the amplitude of the azimuth pulses 108 which is an indication that the elevation angle is twice as great as the azimuth angle. These relative magnitudes are in accord with the position of the target 72 in FIG. 2.
The above three signals, namely the sum, azimuth and elevation signals are the output signals of the conventional simultaneous lobing antenna. Mixing of these signals is accomplished by the switching circuit of this invention which, by combining these signals, derives a single microwave signal.
The fundamental frequency of the master oscillator of the electronic reference generator of FIG. 3 is one-quarter of the pulse repetition rate of the trans mitter incorporated into transceiver 66 which originates the main bang. Hence, there are four main bang pulses to one cycle of the oscillator 80.
The microwave switch 50 of F IG. 1 is actuated by the control signal 92 of FIG. 3 having a frequency twice that of the oscillator. Since the switch is brought to the same position every second pulse, the switch will alternately pass an azimuth signal pulse and an elevation signal pulse to the phase inverter. This is illustrated diagrammatically in FIG. 4 where the output from the switch consists of azimuth signal pulse 108 followed by elevation signal pulse 113 which again is followed by azimuth signal pulse 110 and elevation signal pulse 115.
The pulse inverter 54 of FIG. 1 is actuated by the square wave signal 86 of FIG. 3 which has the same frequency as the oscillator and which will actuate the phase shifter twice during each oscillator cycle. In other words, the phase inverter 54 will let two pulse signals pass through without changing the phase and thereafter invert the phase of the next two pulses. In accordance with the designation of the term positive or in-phase, the inverted phase pulse will be negative. This can be seen diagrammatically in FIG. 4 where pulse 108 and pulse 113 from the switch 50 are permitted to pass freely through the phase inverter whereas pulse 110' and 115' have suffered a 180 phase shift with respect to the pulses from the switch 50.
The output of the phase inverter is then combined with the sum signal in the Y-junction 60. The result of this combination is shown diagrammatically in FIG. 4 where pulse 116 is a combination or addition of pulse 104 and 108, pulse 117 is a combination of pulse 105 and 113, pulse 118 is a combination of pulse 106 and 110, and pulse 119 is a combination of pulse 107 and l 15'. The pulses l 16, 1 17, 118 and 119 provide the single microwave error signal having; an envelope 120 which is the error envelope from which error voltages representative of the azimuth and elevation may be obtained by conventional demodulation taking place within the transceiver 66.
More particularly, the microwave error signal of FIG. 4 whose envelope 120 has the same frequency as the reference signal 82 of FIG. 3 is applied to the standard microwave receiver incorporated into transceiver 66 which has a mixing stage, an IF stage, and which demodulates the microwave error signal to abstract therefrom the envelope 120. Thereafter, the envelope 120 is phase detected by means of the reference signal 82 by standard conical scan tracking methods as are well known to those skilled in the art.
There has been described a method and a means of utilizing a conventional simultaneous lobing antenna and combining the output of this antenna in such a way as to obtain a single microwave error signal which has modulated upon it information representative of the azimuth, the elevation and the range of the target. The switching means used in deriving the microwave error signal employs a microwave switch and a microwave phase inverter both of which are only required to handle very small amounts of wave energy power and which therefore can be very efficiently operated. The advantages which the wave energy tracking system of this invention provide are the use of a simultaneous lobing antenna system having no moving parts and therefore greater mechanical simplicity and a single microwave receiver as used in conical scanning techniques with a resultant saving of weight and space.
What is claimed as new is:
1. In an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal and a reference signal and adapted to develop corresponding demodulated error voltages therefrom,
and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse antenna to said receiver and comprising: a phase inverter; a microwave two-channel switch coupled to said phase inverter and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverte r being responsive to a second control signal to selectively impart a 180 phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal andthe selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
2. In an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal'and a 'reference'signal and adapted todevelop corresponding demodulated error voltages therefrom, and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse I antenna to said receiver and comprising: a phase inverter; an electronic reference generator adapted to develop said reference signal, a first control signal and elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal to sequentially impart a 180 degree phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal and the sequentially phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
3. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the comers of a square, and hybrid junction means having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said hybrid junction means being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit coupling said simultaneous lobing antenna to said receiver, said switching circuit including a phase inverter; a microwave two-channel switch coupled to said phase inverter'and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal to selectively impart a 180 phase shift to the selectively applied azimuth or elevation signal, and adder means coupled to said phase inverter and responsive to said sum signal and the selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom. I I
4. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and hybrid junction means having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of microwave signal received from said target, said hybrid junction means being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit coupling said simultaneous lobing antenna to said receiver, said switching circuit including a phase inverter, an electronic reference generator adapted to develop said reference signal, a first control signal and a second control signal, a microwave two-channel switch coupled to said phase inverter and to said generator and responsive to said first control signal to sequentially apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal to sequentially impart a 180 degree phase shift to the sequentially applied azimuth or elevation signal, and adder means coupled to said phase inverter and responsive to said sum signal and the sequentially phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
5. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave twochannel switch, a microwave phase inverter, and adder means, said switch being coupled to said phase inverter and responsive to a first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal for sequentially introducing a 180 phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
6. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of theazimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave twochannel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing said reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal for sequentially introducing a phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
7. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each'of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter and adder means, said switch being coupled to said phase inverter and responsive to a first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal for sequentially introducing a 180 phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
8. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing an tenna including four symmetrically positioned radiators defining the comers of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing a reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal

Claims (8)

1. In an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals Which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal and a reference signal and adapted to develop corresponding demodulated error voltages therefrom, and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse antenna to said receiver and comprising: a phase inverter; a microwave two-channel switch coupled to said phase inverter and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal to selectively impart a 180* phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal and the selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
1. In an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals Which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal and a reference signal and adapted to develop corresponding demodulated error voltages therefrom, and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse antenna to said receiver and comprising: a phase inverter; a microwave two-channel switch coupled to said phase inverter and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal to selectively impart a 180* phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal and the selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
2. In an electronic lobe switching system for locating a target in space and including a monopulse antenna having three output terminals which provide respectively a sum signal, an azimuth signal and an elevation signal, a receiver responsive to a microwave error signal and a reference signal and adapted to develop corresponding demodulated error voltages therefrom, and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and adapted to develop therefrom said microwave error signal, said switching circuit coupling said monopulse antenna to said receiver and comprising: a phase inverter; an electronic reference generator adapted to develop said reference signal, a first control signal and a second control signal; a microwave two-channel switch coupled to said phase inverter and to said generator and responsive to said first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal to sequentially impart a 180 degree phase shift to the selectively applied azimuth or elevation signal; and adder means coupled to said phase inverter and responsive to said sum signal and the sequentially phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
3. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and hybrid junction means having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said hybrid junction means being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit coupling said simultaneous lobing antenna to said receiver, said switching circuit including a phase inverter; a microwave two-channel switch coupled to said phase inverter and responsive to a first control signal to selectively apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal to selectively impart a 180* phase shift to the selectively applied azimuth or elevation signal, and adder means coupled to said phase inverter and responsive to saId sum signal and the selectively phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
4. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and hybrid junction means having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said hybrid junction means being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit coupling said simultaneous lobing antenna to said receiver, said switching circuit including a phase inverter, an electronic reference generator adapted to develop said reference signal, a first control signal and a second control signal, a microwave two-channel switch coupled to said phase inverter and to said generator and responsive to said first control signal to sequentially apply either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal to sequentially impart a 180 degree phase shift to the sequentially applied azimuth or elevation signal, and adder means coupled to said phase inverter and responsive to said sum signal and the sequentially phase-inverted signal derived from said phase inverter and adapted to develop said microwave error signal therefrom.
5. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; a receiver responsive to a microwave error signal and a reference signal and adapted to develop demodulated error voltages representative of the azimuth and elevation of said target; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal and coupling said simultaneous lobing antenna to said receiver, said switching circuit being adapted to develop said microwave error signal and including a microwave two-channel switch, a microwave phase inverter, and adder means, said switch being coupled to said phase inverter and responsive to a first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal for sequentially introducing a 180* phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
7. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth output terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter and adder means, said switch being coupled to said phase inverter and responsive to a first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being responsive to a second control signal for sequentially introducing a 180* phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and being adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
8. An electronic lobe switching system for locating a target in space comprising: a simultaneous lobing antenna including four symmetrically positioned radiators defining the corners of a square, and a plurality of intercoupled hybrid junctions having four input terminals, a sum output terminal, an azimuth outpuT terminal and an elevation output terminal, each of said radiators being coupled to one of said input terminals and adapted to excite a microwave signal therein representative of a microwave signal received from said target, said plurality of hybrid junctions being adapted to develop a sum signal in said sum terminal, an azimuth signal in said azimuth terminal and an elevation signal in said elevation terminal representative of the range, the azimuth and the elevation of said target respectively; and a switching circuit responsive to said sum signal, said azimuth signal and said elevation signal coupled to said simultaneous lobing antenna, said switching circuit being adapted to develop a microwave error signal and including a microwave two-channel switch, a microwave phase inverter, adder means, and an electronic reference generator for developing a reference signal and first and second control signals, said switch being coupled to said phase inverter and to said generator and responsive to said first control signal for sequentially applying either said azimuth signal or said elevation signal to said phase inverter, said phase inverter being coupled to said generator and being responsive to said second control signal for sequentially introducing a 180 degree phase shift to the sequentially applied azimuth or elevation signal, and adder means coupling said phase inverter to said sum terminal and adapted to mix the sequentially phase-inverted signal from said phase inverter and said sum signal to develop said microwave error signal.
US00658915A 1957-05-01 1957-05-01 Monopulse switching system Expired - Lifetime US3710390A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US00658915A US3710390A (en) 1957-05-01 1957-05-01 Monopulse switching system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00658915A US3710390A (en) 1957-05-01 1957-05-01 Monopulse switching system

Publications (1)

Publication Number Publication Date
US3710390A true US3710390A (en) 1973-01-09

Family

ID=24643238

Family Applications (1)

Application Number Title Priority Date Filing Date
US00658915A Expired - Lifetime US3710390A (en) 1957-05-01 1957-05-01 Monopulse switching system

Country Status (1)

Country Link
US (1) US3710390A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3778829A (en) * 1972-02-18 1973-12-11 Westinghouse Electric Corp Guarded monopulse radar system
US5359329A (en) * 1981-03-18 1994-10-25 The United States Of America As Represented By The Secretary Of The Navy Jammer reference target measurement system
US5982320A (en) * 1986-11-28 1999-11-09 The Marconi Company Limited Radar seeker
US20020105462A1 (en) * 2000-03-14 2002-08-08 Hans Bloecher Device and method for an antenna array with switchable wide-angle coverage

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2464822A (en) * 1943-08-16 1949-03-22 Sperry Corp Indicating device
US2594317A (en) * 1942-11-21 1952-04-29 Sperry Corp Corrected data tracking system
US2597862A (en) * 1945-05-03 1952-05-27 John H Greig Electronic lobing
US2759154A (en) * 1954-11-10 1956-08-14 Sperry Rand Corp Waveguide hybrid network for monopulse comparator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2594317A (en) * 1942-11-21 1952-04-29 Sperry Corp Corrected data tracking system
US2464822A (en) * 1943-08-16 1949-03-22 Sperry Corp Indicating device
US2597862A (en) * 1945-05-03 1952-05-27 John H Greig Electronic lobing
US2759154A (en) * 1954-11-10 1956-08-14 Sperry Rand Corp Waveguide hybrid network for monopulse comparator

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3778829A (en) * 1972-02-18 1973-12-11 Westinghouse Electric Corp Guarded monopulse radar system
US5359329A (en) * 1981-03-18 1994-10-25 The United States Of America As Represented By The Secretary Of The Navy Jammer reference target measurement system
US5982320A (en) * 1986-11-28 1999-11-09 The Marconi Company Limited Radar seeker
DE3744739C2 (en) * 1986-11-28 1999-12-02 Marconi Gec Ltd Radar seeker
US20020105462A1 (en) * 2000-03-14 2002-08-08 Hans Bloecher Device and method for an antenna array with switchable wide-angle coverage
US6954176B2 (en) * 2000-03-14 2005-10-11 Daimlerchrysler Ag Device and method for an antenna array with switchable wide-angle coverage

Similar Documents

Publication Publication Date Title
US4329687A (en) Radar radiating polarized signals
US4849762A (en) Single-transmission polarization signal extractor
US3175215A (en) Single channel monopulse radar system
KR930701756A (en) Monopulse processing system
US3107351A (en) Radar resolutions
US3349394A (en) Radar sensing system
US3378843A (en) Monopulse tracking radar system capable of locating a plurality of unresolved targets
US3710390A (en) Monopulse switching system
US4868917A (en) Radar arrangements
EP0138253A2 (en) Noise reduction in CW radar systems
US3716856A (en) Polarization adaptive mti radar transponder
US2931033A (en) Multi-mode automatic tracking antenna system
US5093666A (en) Lobing system
US3371341A (en) Method and means for extracting velocity sense from a non-coherent janus doppler rada system
US3495246A (en) Antenna energizing arrangement for direction finding utilizing amplitude comparison
US3618093A (en) Obstacle detection radar system
US3309708A (en) Tactical landing approach radio system
US3078453A (en) Radar system for distinguishing closely spaced targets
US3026513A (en) Dual beam tracking system
US3962705A (en) Radar microwave lobing systems
US4005414A (en) Method for providing means to eliminate ambiguous polarization effects on phase and amplitude of radar backscatter due to unknown target aspect angle
US3882500A (en) System for the automatic tracking of a moving target
US3893116A (en) Radar lobing system
US3438030A (en) Object detection system
US3359554A (en) Radar-beacon system with two-way communication capability