US3680108A - Self-steering array repeater - Google Patents

Self-steering array repeater Download PDF

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US3680108A
US3680108A US44715A US3680108DA US3680108A US 3680108 A US3680108 A US 3680108A US 44715 A US44715 A US 44715A US 3680108D A US3680108D A US 3680108DA US 3680108 A US3680108 A US 3680108A
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phase
signal
elements
received
portions
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US44715A
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Thomas Lawrence Osborne
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AT&T Corp
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Bell Telephone Laboratories Inc
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    • 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
    • G01S3/38—Systems for determining direction or deviation from predetermined direction using adjustment of real or effective orientation of directivity characteristic of an antenna or an antenna system to give a desired condition of signal derived from that antenna or antenna system, e.g. to give a maximum or minimum signal
    • G01S3/42—Systems for determining direction or deviation from predetermined direction using adjustment of real or effective orientation of directivity characteristic of an antenna or an antenna system to give a desired condition of signal derived from that antenna or antenna system, e.g. to give a maximum or minimum signal the desired condition being maintained automatically
    • 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
    • H01Q3/26—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 relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/30—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 relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
    • H01Q3/34—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 relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means
    • H01Q3/42—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 relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means using frequency-mixing

Definitions

  • ABSTRACT [22] Filed: June 9, 1970 A self-steering phased antenna array repeater system in which [211 App] 44 715 signals from a distant source at two spaced receptors are relatively shifted in phase and combined in a square law mixer.
  • the output mixer current is a function of their phase dif- 1 "343/10o Tn, 343/ 1 A ference and indicates the direction in which the signals arrive.
  • luLCl [22] Filed: June 9, 1970 A self-steering phased antenna array repeater system in which [211 App] 44 715 signals from a distant source at two spaced receptors are relatively shifted in phase and combined in a square law mixer.
  • the output mixer current is a function of their phase dif- 1 "343/10o Tn, 343/ 1 A ference and indicates the direction in which the signals arrive.
  • phase shifting circuits are slow acting and the systems employing them are generally not capable of full diplex operation, i.e., continuous and simultaneous transmission and reception. Further, the phase shifters are a substantial source of radio frequency loss and when included in the receiving path become a source of loss not easily overcome by amplification. Further, specifically designed and relatively complicated control circuits are required to drive the phase shifters.
  • a self-steering system requiring no pilot signals, no phase shifters of the usual type, and capable of full diplex operation at different transmission frequencies. It has been recognized that if the signals from a distant source at two spaced receptors are shifted relative to each other by 90 and mixed in a square law detector, the output current will be a sine function of their phase difference and will indicate the direction in which the signals arrive at' the receptors. This current is then used to bring the phase of received signals together for combining and to introduce the same phase angle but of opposite sign to transmitted signals for reradiation toward the source.
  • injection locked oscillators are used to produce the receiving and transmitting phase shifts and since these oscillators produce a phase shift according to the same sine function as the mixer output current, they are inherently compatible therewith.
  • an injection locked oscillator is included in the coupling paths between the antenna elements and the common output for received signals in all but one path, which is considered the reference path. Similar oscillators are included in each of the coupling paths other than the reference path between the common source for the transmitted signal and each radiating element of the antenna array.
  • the injection locked oscillator may be included directly in the path as a special form of variable phase shifter or included indirectly in the path as the local oscillator supplying a particularly phased signal to a modulator interposed in the path.
  • FIG. 1 is a block diagram illustrating a self-steering antenna array repeater system in accordance with the invention
  • FIG. 2 illustrates circuit details of the square law mixer-detector and the injection locked oscillators for the circuits shown as blocks in the system of FIG. 1;
  • FIG. 3 is a block diagram illustrating a self-steering array repeater in accordance with a second embodiment of the invention.
  • FIG. 4 represents a modification of the polarity connections of FIG. 2 as required in the embodiment of FIG. 3.
  • FIG. I a system of this type is illustrated by an array of equally spaced nondirective receiving and radiating antenna elements A,,, A, to A,,, all being fed oblique ly by radio waves 10 from remote station 11.
  • FIG. 1 illustrates the circuits connected to elements A and A,, it being understood that other elements A have circuits identical to A, as represented by the box 12.
  • the signal received and transmitted on element A is assumed to be the one with which the phase of the other signals is compared, it will be referred to as the reference signal and may be designated E sin wt, where w is the angular frequency of the carrier.
  • the signal received on A may carry intelligence in the form of frequency modulation, no term is included to represent this modulation in order to simplify the mathematics which follows.
  • Elements A and A are connected to suitable diplexers, which may, for example, be circulators l3 and 14, respectively, which separate the received waves from those to be transmitted.
  • the outputs from the second ports of circulators l3 and 14 are respectively applied to limiter-amplifiers l5 and 16 which insure that the signal amplitudes are relatively constant with time.
  • the primary coupling path for receiving the directed signal can then be traced from the second or receiving port of circulator 14 to amplifier 16, through an injection locked oscillator 20, by which it will be brought into a common phase with the reference signal on bus 28, where it is combined with the reference signal from circulator 13 and amplifier 15 for delivery at R.F. OUT to a common apparatus 22 for utilizing the received signals.
  • the primary coupling path for transmitting the directed signal can similarly be traced from R.F. IN and the common source 23 of the transmitted signals.
  • the signals to be transmitted are first divided into portions on bus 29 with one portion for each radiating element.
  • One such of these portions is delivered to injection locked oscillator 21 by which it is shifted in phase relative to the reference signal and then coupled to the third or transmitting port of circulator 14.
  • the path for the one portion comprising the reference signal extends from RR IN to the transmitting port of circulator 13.
  • the control path on the other hand includes a square-law mixer-detector 24 connected to receive a sample of both the reference signal and the directed signal.
  • a sample of the reference signal is coupled through a fixed degree phase shifter 25 which converts its form to E sin(wl 90) or E cos wt.
  • This phase shifted sample of the reference signal which is now nearly in quadrature with the directed signal E sin(mt is then fed along with a sample of the directed signal to mixer-detector 24 which combines the two samples, squares them and delivers a rectified output direct current to buses 26 and 26a.
  • mixer 24 and the equations which govern its operation will be given in detail hereinafter.
  • phase shifter 25 For the present, however, assume that it derives a signal that is a given function of (i) such that current on buses 26 and 26a is a function of (b and is applied to control the operation of injection locked oscillators 20 and 21.
  • the phase shifted reference signal from phase shifter 25 is also fed to identical circuits connected to other antenna elements A as shown by bus 27.
  • Circuits l2 similarly introduce uniquely different phase shifts to the transmitted signals to be radiated by antenna elements A each in response to the difference in the phase of the directed signal received by that antenna element and the phase of the received reference signal on antenna element A
  • detector 24 is a balanced mixer and includes a pair of square law diodes d and d These diodes may typically be Shottky barrier diodes or any of a number of other general purpose rectifying diodes.
  • Diodes d, and d are fed in push-pull by transformer 41 having the signal E sin(wt 4)) applied thereto and in parallel by transformer 42 having the signal E cos not applied thereto.
  • Resistors 43 and 44 having a sum resistance R comprise the respective diode loads and capacitors 45 and 46 comprise radio frequency bypass filters.
  • Resistances 43 and 44 are each much smaller than the diode resistances so that the current in each resistor is essentially equal to its associated diode current. Since the diodes follow a square law, these diode currents are in turn proportional to the square of the voltages e, and 0. applied to the diodes. Thus. the net output voltage is the difference between the individual diode contributions and can be expressed Note further that h E cos wt E sin(w! +l and Substituting Equations (3) in Equation (2), expanding, and dropping all terms which cancel:
  • a preferred embodiment ofthe invention employs a single operational amplifier or do amplifier stage having a high input impedance and a low output impedance. Further, it is preferred that separate amplifiers 47 and 48 be provided to separately drive each of the injection locked oscillators 20 and 21.
  • the output voltage s of each amplifier (this being the voltage on bus 26 or bus 26a of FIG. 1) can then be expressed as c K sin d:
  • K is a constant including the gain of the amplifier.
  • oscillator 21 which will be considered by way of illustration, may be one employing an IMPATT (impact Avalanche and Transit Time) diode 51 as described in the paper The lMPA'I'T Diode A Solid State Microwave Generator," 45 Bell Labs Record I44, May 1967 or in the copending application of B. C. DeLoach, Jr. et al., Ser. No. 883,898, filed Dec. 10, 1969, or in the copending application of B. Glance, Ser. No. 812,04l, filed Apr. l, 1969.
  • IMPATT impact Avalanche and Transit Time
  • Capacitor 53 and choke inductance 54 represents the required decoupling circuit between bias sources and the radio frequency circuit.
  • the injected signal input for locking is applied to the first port 56 of circulator 55 which couples it to the radio frequency circuit of diode 51 illustrated schematically by the dotted inductance 52 coupled to the diode and to the second port 57 of circulator 55.
  • the output power is taken from the third port 58 of circulator 55.
  • IMPATF diode 51 when biased to the proper operating point by bias source 50 (in series with the voltage e from amplifier 48) has the relation AI Alb/K (7) between a change Aw in the natural resonant frequency w and the change AI in the bias current where K, is a constant diode parameter.
  • the output 58 When the oscillator is synchronized byan injection signal E sin wt as supplied over input 56, the output 58 will comprise a signal having the same frequency to as the injection signal but displaced therefrom by a phase d which depends directly upon Aw according to the relation sin (Po 8 where Q is the external circuit 0 of the oscillator, G is the ratio of the output power to the injected power of the oscilla tor.
  • Q is the external circuit 0 of the oscillator
  • G the ratio of the output power to the injected power of the oscilla tor.
  • this bias current includes a fixed component due to source 50 and an incremental component due to c
  • the fixed current is proportional to the voltage from source 50 and is adjusted to set the natural resonant frequency w to equal that of the injection signal in the absence of an incremental current, i.e., when e is zero.
  • the incremental current from Equation (6) is A, T Rt:
  • Equation (8) is the equivalent d.c. resistance of the diode bias circuit.
  • Equation (8) is the equivalent d.c. resistance of the diode bias circuit.
  • Equation (8) leads to sin tp" sin 1p. (Hi) It is then a simple matter to proportion all constants enclosed within the brackets of Equation (10) so that the bracketed portion equals unity.
  • sin qb sin This means that the sine function current derived from mixer-detector 24 is exactly the function required to cause injection locked oscillator 58 to introduce the phase shift required as described with reference to FIG. 1. The sign of the introduced phase shift depends upon the particular kind of diode employed.
  • phase shift will have the same sign as Ai meaning that the natural resonant frequency increases with bias.
  • connection as indicated by the polarity designations on amplifiers 47 and 48 are proper to obtain a negative or phase delay. Reversing these connections would produce a positive 45 as required in an embodiment to be described hereinafter.
  • Oscillator 20 is identical to oscillator 21 and similarly shifts the injected signal by 1),, equal to Since the sine function current is ambiguous for angles greater than :90", the number of elements in the antenna array and the distance d between them should be selected according to Equation (1) so that need not exceed i90 for the required steering angle.
  • the invention involves substantial advantages over prior art systems. For example, no particular qualities, such as a pilot, are required of the signal from the remote station 11. Further, the invention is capable of full diplex operation. While illustrated for convenience as using the same frequency for transmission and reception, it is obvious that the injection locked oscillators 20 and 21 need not operate at the same frequency and that proper scaling thereof and of amplifiers 47 and 48 allows transmission and reception at frequencies removed from each other as required in practice.
  • the system of FIG. 1 has, however, certain limitations stemming from the fact that the locking or injected signal for the locked oscillators 20 and 21 comprises the intelligence bearing signal itself. Equation (8) and the factor G thereofindicate that the amplitude of the injected signal must be con stant for a given phase shift leading to the use of limiting amplifiers l and 16 and precluding the use of amplitude modulation on the carrier. Further, since injection locked oscillators 20 and 21 are interposed directly in the primary receiving and transmitting paths, they will have the effect of somewhat limiting the modulation index of a frequency or phase modulated carrier.
  • the improvement stems from the fact that the injection locked oscillators are isolated from the primary signal paths by modulators and their locking signals are derived independently from stable oscillators. This feature allows substantial flexibility in choice of both the receiving and transmitting frequencies and further allows the output and input frequencies to be at an IF frequency without a further frequency conversion stage.
  • FIG. 3 For convenience, corresponding reference numerals have been used in FIG. 3 to designate components corresponding to those of FIG. 2. The principal difference will be seen to reside in the directed signal coupling paths wherein receiving modulator 30 is now interposed in the receiving path from element A, and a transmitting modulator 31 is interposed in the transmitting path thereto.
  • These modulators are both of the form typically employed as the up and down converters in high frequency equipment.
  • the signal corresponding to the usual local oscillator is, however, derived from the output of injection locked oscillators 32 and 33, respectively. As illustrated, each oscillator 32 and 33 has an output frequency that is different from the desired receiving and transmitting frequency by the required IF frequency. These transmitting and receiving frequencies may be selected independently of each other.
  • the locking signals for injection locked oscillators 32 and 33 are respectively supplied by receiving and transmitting local oscillators 34 and 34a having fixed amplitudes and stable frequencies equal to the desired output frequency of the respective locked oscillator.
  • the natural resonant frequency of each locked oscillator 32 and 33 is controlled by the voltage on buses 26 and 26a as described above (a function of the phase differential 4) of the signals received by element A and A,).
  • the reference signal coupling paths include receiving modulator 3S and transmitting modulator 36 in the paths to element A in order to convert to and from the IF frequency, if required, but not to introduce any change in phase.
  • Modulators 35 and 36 are supplied by local oscillator power derived from the same sources 34 and 34a respectively, noted above which, however, are shown in order to simplify the drawing as separate sources.
  • E sin to! is received by element A and applied to modulator 35.
  • E sin(wt is received by element A, and applied to modulator 30.
  • Local oscillator 34 will have a frequency w where w a) is the IF frequency m
  • the output from locked oscillator 32 will be E sin(w t (12 and mixed in modulator 30 with E sin(wt (1)), the difference product delivered to bus 28 will be E K sin [(19 w t+ d) (0 where K, is the conversion constant.
  • the same conversion, but without phase change, takes place in modulator 35 becoming E sin m t so that the outputs from modulators 30 and 35 will be combined coherently on bus 28 with the outputs from similar circuits in box 38.
  • this reversal may be obtained in several ways including a reversal of the polarity connection of the voltage 2 to the operational amplifier 48a which drives the transmitting injection locked oscillator 33 so that signal from amplifier 48a is e,,, the reverse of e from amplifier 47 and from amplifier 48 of FIG. 2.
  • E sin w,,.-t is received on IF IN and divided on bus 29.
  • Transmitting local oscillator 34a will have a frequency (w to where 00 is the desired transmitting frequency.
  • the frequency of the reference signal radiated by element A will be converted to the transmission frequency as E sin m without phase change by modulator 36.
  • the output from locked oscillator 33 will be in the form E sin [(w w t 4)] and when mixed in modulator 31 with E sin (o t, the sum product radiated by element A, will be E K, sin(w -t as required for retransmission in the same direction as the signal received.
  • receiver modulator 30 and transmitter modulator 31 may be fed by the same injection locked oscillator provided that the desired transmitting and receiving frequencies are not greatly different and provided that modulator 31 is adapted by known design to invert the phase of the carrier signal relative to the oscillator signal as compared to these phases in modulator 30.
  • High frequency directional apparatus comprising a plurality of antenna elements arranged in an array
  • High frequency radio apparatus comprising at least two antenna elements arranged in an array,
  • High frequency radio apparatus comprising at least two antenna elements arranged in an array,
  • High frequency radio apparatus comprising at least two antenna elements arranged in an array,
  • means responsive to said function for changing the phase of one of said divided portions relative to another comprising an injection locked oscillator and including means for controlling the natural resonant frequency of said oscillator in response to said function
  • injection locked oscillator has its locking signal input connected to receive said one divided portion and its output coupled to one of said radiating elements.
  • the apparatus of claim 5 including a high frequency mixing circuit interposed in the path of said one divided portion and wherein said injection locked oscillator supplies a signal to be mixed in said mixer with said divided portion,
  • the apparatus of claim 5 including a second mixing circuit and a second injection locked oscillator responsive to said function for changing the phase of the remaining portion received on one ofsaid elements, and
  • High frequency radio apparatus comprising at least two antenna elements arranged in an array
  • said means for deriving includes a square-law mixer and means for applying said portions to said mixer in quadrature so that the output of said mixer is a sine function of said phase angle and wherein each ofsaid means for changing phase comprise an injection locked oscillator having a bias current for controlling the natural resonant frequency of said oscillator supplied by the output of said mixer.
  • the apparatus of claim 10 including a high frequency mixing circuit interposed in the path of one of said remaining portions and one of said divided portions and wherein said injection locked oscillator supplies a signal to be mixed in said mixer with said portions.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Radar Systems Or Details Thereof (AREA)
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US44715A 1970-06-09 1970-06-09 Self-steering array repeater Expired - Lifetime US3680108A (en)

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BE (1) BE768190A (OSRAM)
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996008849A3 (en) * 1994-09-14 1996-05-30 Philips Electronics Nv A radio transmission system and a radio apparatus for use in such a system
EP0700116A3 (en) * 1994-08-29 1998-01-07 Atr Optical And Radio Communications Research Laboratories Apparatus and method for controlling array antenna comprising a plurality of antenna elements with improved incoming beam tracking
US20060262013A1 (en) * 2005-05-18 2006-11-23 Shiroma Grant S Full-duplex dual-frequency self-steering array using phase detection & phase shifting
US20110002428A1 (en) * 2009-07-02 2011-01-06 Bruce Erickson Apparatus and method for reducing third-order intermodulation distortion
US20110234446A1 (en) * 2010-03-25 2011-09-29 Patrick David E Apparatus for measuring the relative direction of a radio signal
CN109212515A (zh) * 2017-07-07 2019-01-15 中山大学 主动式相位切换阵列

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2360635B (en) * 1998-02-24 2002-06-26 Univ Belfast Retroreceive antenna
JP5446671B2 (ja) * 2009-09-29 2014-03-19 ソニー株式会社 無線伝送システム及び無線通信方法
GB2524529A (en) * 2014-03-25 2015-09-30 Univ Belfast Tracking antenna system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3394374A (en) * 1961-08-11 1968-07-23 Packard Bell Electronics Corp Retrodirective antenna array

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3036210A (en) * 1959-11-02 1962-05-22 Space General Corp Electronically scanning antenna empolying plural phase-locked loops to produce optimum directivity
US3175216A (en) * 1962-08-28 1965-03-23 Bell Telephone Labor Inc Communication station employing antenna array
US3300782A (en) * 1963-07-08 1967-01-24 Electronic Specialty Co Comunications repeater system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3394374A (en) * 1961-08-11 1968-07-23 Packard Bell Electronics Corp Retrodirective antenna array

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0700116A3 (en) * 1994-08-29 1998-01-07 Atr Optical And Radio Communications Research Laboratories Apparatus and method for controlling array antenna comprising a plurality of antenna elements with improved incoming beam tracking
WO1996008849A3 (en) * 1994-09-14 1996-05-30 Philips Electronics Nv A radio transmission system and a radio apparatus for use in such a system
US20060262013A1 (en) * 2005-05-18 2006-11-23 Shiroma Grant S Full-duplex dual-frequency self-steering array using phase detection & phase shifting
US20110002428A1 (en) * 2009-07-02 2011-01-06 Bruce Erickson Apparatus and method for reducing third-order intermodulation distortion
US8446997B2 (en) * 2009-07-02 2013-05-21 Agilent Technologies, Inc. Apparatus and method for reducing third-order intermodulation distortion
US20110234446A1 (en) * 2010-03-25 2011-09-29 Patrick David E Apparatus for measuring the relative direction of a radio signal
CN109212515A (zh) * 2017-07-07 2019-01-15 中山大学 主动式相位切换阵列

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GB1325955A (en) 1973-08-08
BE768190A (fr) 1971-11-03
SE363432B (OSRAM) 1974-01-14
JPS5543284B1 (OSRAM) 1980-11-05
FR2094144B1 (OSRAM) 1977-01-21
DE2128082A1 (de) 1971-12-16
FR2094144A1 (OSRAM) 1972-02-04

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