US2422110A - Omnidirectional radio range - Google Patents

Omnidirectional radio range Download PDF

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Publication number
US2422110A
US2422110A US460292A US46029242A US2422110A US 2422110 A US2422110 A US 2422110A US 460292 A US460292 A US 460292A US 46029242 A US46029242 A US 46029242A US 2422110 A US2422110 A US 2422110A
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frequency
modulation
phase
azimuth
component
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US460292A
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David G C Luck
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RCA Corp
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RCA Corp
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Priority to GB1?097/44A priority patent/GB594532A/en
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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
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves

Definitions

  • This invention relates to omnidirectional radio ranges, and particularly to the provision of reference phase signals for such systems.
  • One type of omnidirectional range is described in U. S. Patent No. 2,208,376 to D. G. C. Luck.
  • A. continuous wave carrier is radiated with a limacoid directive pattern.
  • the directive pattern is continuously rotated, so that the signal picked up by a receiver is sinusoidally modulated at the pattern rotation frequency.
  • the modulation phase depends on the direction of the receiver from the transmitter. It is necessary to provide a constant phase reference for comparison with the pattern rotation 'modulation at the receiver in order to provide azimuth indication.
  • the principal object of the present invention is to provide an improved omnidirectional radio range with an improved reference phase transmission, in which the use' of a subcarrier or of impulsive keying is avoided.
  • Another object is to provide an improved omnidirectional radio range system affording coarsel and ne azimuth indications.
  • the directive transmission is made by causing a eld pattern to rotate at a uniform speed, while the reference transmission is made by modulating a non-directionally transmitted carrier at a frequency subharmonically related to the pattern rotation frequency.
  • the non-directional carrier is of the same frequency as that used for the directional transmission.
  • a fixed phasal relation is maintained at the transmitter between the pattern rotation and the non-directional modulation.
  • the pattern rotation and reference modulations are separated by lilters.
  • the frequency of the reference modulation is multiplied to equal that of the directional modulation, and the relative phase of the two voltages indicated by a synchroscope, or the like.
  • Fig. l is a schematic block diagram of a range transmitter according to the invention
  • Fig. 2 is a similar diagram of a range receiver.
  • orthogonally related pairs of opposed antennas N S and E, W are connected to the outputs of a pair of balanced modulators I and 3, respectively.
  • a radio frequency oscillator 5 is connected through an amplifier l a. to the modulators I and 3 and to a power amplier 9.
  • the amplifier 9 is connected to a nondirective antenna I I.
  • An oscillator I3 is connected through a frequency divider I5 to the balanced modulator I.
  • the output of the frequencydivider I5 is also connected through a 90 phase shifter I'I to the balanced modulator 3.
  • a second frequency divider I9 is connected between the output of the frequency divider I5 and a combining circuit 2I.
  • a modulator 23 is arranged to modulate the power amplifier 9 under the control of the output of the combining circuit 2
  • Fig. 2 is a schematic block diagram of a range receiver system according to the invention.
  • a radio receiver 25 is connected to an antenna 2l.
  • the output of the receiver 25 is connected to lters 29, 3l and 33.
  • the output of the lter 29 is connected directly to one of the usual orthogonally related deflection circuits of a cathode ray tube 35 and through a'90 phase shifter 3l to the other deflection circuit of the tube 35.
  • the output of the iilter 33 is applied to a frequency multiplier 34, which is similarly connected to the orthogonal deflection circuits of a second cathode ray tube 39.
  • a second 90 phase shifter lll is provided for the tube 39.
  • the cathode ray tubes 35 and 39 are provided with radial deflection electrodes. The radial deflection electrodes of the two tubes are connected together through an impulse Shaper circuit 43 to the output of the lter 3
  • the operation of the system is as follows:
  • the oscillator 5 provides a carrier voltage which is amplied by the amplier 'I and applied to the balanced modulators I and 3 and the power amplier 9.
  • the oscillator I3 provides a frequency of, for example, 720 cycles per second.
  • the frequency divider I5 is adjusted for l2 to 1 frequency division, providing an output of cycles per second.
  • This voltage controls the balanced modulators I and 3, providing a rotating eld of radiation from the antennas N, S, E and W, as described more fully in the aforementioned patent.
  • the output of the ampliiier 3 is radiated non-directionally by the antenna I I, modifying the iigure-of-eightl pattern of the antennas N, S, E and W to provide the limacoid pattern.
  • Reference phase modulation is impressed on the non-directional carrier by modulation of the power amplifier 9.
  • the frequency divider I0 is arranged for 3 to 1 division, providing an output of 20 cycles per second for controlling the modulator 23.
  • the output cathode ray beam of the tube 35Y to trace a circular path at the rate of '720 times per second.
  • the 20 cycle component is converted to 60 cycles by the multiplier 3G, causing the beam of the tube 39 to trace a circular path 60 times per second.
  • the 60 cycle variable phase modulation component is vconverted by the impulse Shaper 43 to a sharp pulse repeating at intervals of onesixtieth second, coinciding with the peaks of the modulation from which it is derived. This pulse is applied to the radial deflection circuits of both cathode ray tubes 35 and 39, providing deflections 45 and lll of the traces i9 and 5l.
  • the coarse indicator tube 39 traces one circle for each pulse, while the fine indicator 35 traces l2 circles during the same period.
  • the face of the tube 39 may be calibrated to indicate angles up to one-twelfth of a circle, or 30 degrees.
  • the tube 39 indicates the approximate bearing of the range transmitter as over 30 and less than 60, and the tube 35 shows that the exact bearing is eleven and one-half degrees east of the rst full thirty degrees.
  • the exact bearing is th-us 30 ⁇ plus 11%, or 4119
  • the range receiver is provided with filters for separating the reference modulation from the pattern rotation modulation.
  • the reference modulation is multiplied in frequency to provide a constant phase Voltage equal in frequency to the variable phase directional modulation voltages.
  • the two voltages are applied to a phase indicator calibrated to read azimuth.
  • An omnidirectional radio range system including means for radiating a radio frequency carrier in a rotating directive eld pattern and means for changing the shape of said pattern cyclically at frequencies harmonically related to the frequency of said pattern rotation whereby said carrier is modulated at one frequency with a phase depending upon azimuth and at other frequencies independent of azimuth, means for receiving and demodulating said carrier to produce a signal corresponding to the composite modulation thereof, lter means arranged to separate the components of said signal, means arranged to change the frequency of one of said components to a frequency equal to that of said pattern rotation, a phase responsive indicator device arranged to compare said latter component with the modulation derived from said pattern rotation to provide a coarse unique indication, and a second phase responsive indicator device arranged to compare said pattern rotation modulation component with a higher :frequency component to provide a ne indication.
  • An omnidirectional radio range system including means for radiating a carrier wave including two modulation components of constant azimuthal phase and means for radiating a suppressed carrier wave including a modulation component of phase depending upon azimuth, said three modulation components being of different and harmonically related frequencies; a receiver including means for demodulating said carrier Wave and means for separating said modulation components of different frequencies, means for changing the frequency of one of said constant phase components to a frequency equal to that of said component of variable azimuthal phase, means for comparing said frequency changed component with said variable phase component to provide a unique coarse indication of azimuth, and means for comparing the other of said constant phase components with said variable phase component to provide a ne indication of azimuth.
  • the method of providing azimuth information including the steps of radiating a suppressed carrier wave with a modulation component of phase depending upon azimuth radiating a carrier wave with two modulation components of constant phases, said three modulation components being of different and harmonically related frequencies, receiving and demodulating said waves, separating said modulation components of different frequencies, changing the frequency of one of said constant phase components to a frequency equal to that of said component of azimuthally dependent phase, comparing said frequency changed component with said constant phase component to provide a unique coarse indication of azimuth, and comparing the other of said constant phase components with said component of azimuthally dependent phase to provide a iine indication of azimuth.

Description

June 10, D, Q Q LUCK 2,422,110
O MNIDIRECTIONAL RADIO RANGE Filed Sept. 30,1942
Snventor UCK (Ittomeg Patented June 10, 1947 ZZ l@ e OMNIDIRECTIONAL RADIO RANGE David G. C. Luck, Hightstown, N. J., assigner to Radio Corporation of America, a corporation of Delaware Application September 30, 194,2, Serial No. 460,292
(Cl. Z50-11) 3 Claims. l
This invention relates to omnidirectional radio ranges, and particularly to the provision of reference phase signals for such systems. One type of omnidirectional range is described in U. S. Patent No. 2,208,376 to D. G. C. Luck. A. continuous wave carrier is radiated with a limacoid directive pattern. The directive pattern is continuously rotated, so that the signal picked up by a receiver is sinusoidally modulated at the pattern rotation frequency. The modulation phase depends on the direction of the receiver from the transmitter. It is necessary to provide a constant phase reference for comparison with the pattern rotation 'modulation at the receiver in order to provide azimuth indication. 'Ihis has been done by impressing the reference signal on a subcarrier, or by distorting the reference signal to an impulsive shape, so that as the modulation peak occurs due north of the transmitter, for eX- ample, a brief impulse is radiated.
The principal object of the present invention is to provide an improved omnidirectional radio range with an improved reference phase transmission, in which the use' of a subcarrier or of impulsive keying is avoided.
Another object is to provide an improved omnidirectional radio range system affording coarsel and ne azimuth indications.
In accordance with this invention, the directive transmission is made by causing a eld pattern to rotate at a uniform speed, while the reference transmission is made by modulating a non-directionally transmitted carrier at a frequency subharmonically related to the pattern rotation frequency. The non-directional carrier is of the same frequency as that used for the directional transmission. A fixed phasal relation is maintained at the transmitter between the pattern rotation and the non-directional modulation.
At the receiver the pattern rotation and reference modulations are separated by lilters. The frequency of the reference modulation is multiplied to equal that of the directional modulation, and the relative phase of the two voltages indicated by a synchroscope, or the like.
Referring to the drawing, Fig. l is a schematic block diagram of a range transmitter according to the invention, and Fig. 2 is a similar diagram of a range receiver.
At the range transmitter, orthogonally related pairs of opposed antennas N S and E, W are connected to the outputs of a pair of balanced modulators I and 3, respectively. A radio frequency oscillator 5 is connected through an amplifier l a. to the modulators I and 3 and to a power amplier 9. The amplifier 9 is connected to a nondirective antenna I I.
An oscillator I3 is connected through a frequency divider I5 to the balanced modulator I. The output of the frequencydivider I5 is also connected through a 90 phase shifter I'I to the balanced modulator 3. A second frequency divider I9 is connected between the output of the frequency divider I5 and a combining circuit 2I. A modulator 23 is arranged to modulate the power amplifier 9 under the control of the output of the combining circuit 2|.
Fig. 2 is a schematic block diagram of a range receiver system according to the invention. A radio receiver 25 is connected to an antenna 2l. The output of the receiver 25 is connected to lters 29, 3l and 33. The output of the lter 29 is connected directly to one of the usual orthogonally related deflection circuits of a cathode ray tube 35 and through a'90 phase shifter 3l to the other deflection circuit of the tube 35.
The output of the iilter 33 is applied to a frequency multiplier 34, which is similarly connected to the orthogonal deflection circuits of a second cathode ray tube 39. A second 90 phase shifter lll is provided for the tube 39. The cathode ray tubes 35 and 39 are provided with radial deflection electrodes. The radial deflection electrodes of the two tubes are connected together through an impulse Shaper circuit 43 to the output of the lter 3|.
The operation of the system is as follows: The oscillator 5 provides a carrier voltage which is amplied by the amplier 'I and applied to the balanced modulators I and 3 and the power amplier 9. The oscillator I3 provides a frequency of, for example, 720 cycles per second. The frequency divider I5 is adjusted for l2 to 1 frequency division, providing an output of cycles per second. This voltage controls the balanced modulators I and 3, providing a rotating eld of radiation from the antennas N, S, E and W, as described more fully in the aforementioned patent. The output of the ampliiier 3 is radiated non-directionally by the antenna I I, modifying the iigure-of-eightl pattern of the antennas N, S, E and W to provide the limacoid pattern.
Reference phase modulation is impressed on the non-directional carrier by modulation of the power amplifier 9. The frequency divider I0 is arranged for 3 to 1 division, providing an output of 20 cycles per second for controlling the modulator 23. To provide iine indications of azimuth,
as will appear more fully hereinafter, the output cathode ray beam of the tube 35Y to trace a circular path at the rate of '720 times per second. The 20 cycle component is converted to 60 cycles by the multiplier 3G, causing the beam of the tube 39 to trace a circular path 60 times per second. YThe 60 cycle variable phase modulation component is vconverted by the impulse Shaper 43 to a sharp pulse repeating at intervals of onesixtieth second, coinciding with the peaks of the modulation from which it is derived. This pulse is applied to the radial deflection circuits of both cathode ray tubes 35 and 39, providing deflections 45 and lll of the traces i9 and 5l.
The coarse indicator tube 39 traces one circle for each pulse, while the fine indicator 35 traces l2 circles during the same period. The face of the tube 39 may be calibrated to indicate angles up to one-twelfth of a circle, or 30 degrees. Thus the tube 39 indicates the approximate bearing of the range transmitter as over 30 and less than 60, and the tube 35 shows that the exact bearing is eleven and one-half degrees east of the rst full thirty degrees. The exact bearing is th-us 30` plus 11%, or 4119 Thus the invention has been described as an improved method of and means for providing reierence phase transmission for omnidirectional radio ranges. A constant phase modulation at a subharmonic of the pattern rotation frequency is impressed on the non-directional carrier radiated by the sense antenna of the range transmitter array. The range receiver is provided with filters for separating the reference modulation from the pattern rotation modulation. The reference modulation is multiplied in frequency to provide a constant phase Voltage equal in frequency to the variable phase directional modulation voltages. The two voltages are applied to a phase indicator calibrated to read azimuth.
I claim as my invention:
1. An omnidirectional radio range system including means for radiating a radio frequency carrier in a rotating directive eld pattern and means for changing the shape of said pattern cyclically at frequencies harmonically related to the frequency of said pattern rotation whereby said carrier is modulated at one frequency with a phase depending upon azimuth and at other frequencies independent of azimuth, means for receiving and demodulating said carrier to produce a signal corresponding to the composite modulation thereof, lter means arranged to separate the components of said signal, means arranged to change the frequency of one of said components to a frequency equal to that of said pattern rotation, a phase responsive indicator device arranged to compare said latter component with the modulation derived from said pattern rotation to provide a coarse unique indication, and a second phase responsive indicator device arranged to compare said pattern rotation modulation component with a higher :frequency component to provide a ne indication.
2. An omnidirectional radio range system, including means for radiating a carrier wave including two modulation components of constant azimuthal phase and means for radiating a suppressed carrier wave including a modulation component of phase depending upon azimuth, said three modulation components being of different and harmonically related frequencies; a receiver including means for demodulating said carrier Wave and means for separating said modulation components of different frequencies, means for changing the frequency of one of said constant phase components to a frequency equal to that of said component of variable azimuthal phase, means for comparing said frequency changed component with said variable phase component to provide a unique coarse indication of azimuth, and means for comparing the other of said constant phase components with said variable phase component to provide a ne indication of azimuth.
3. In an omnidirectional radio range, the method of providing azimuth information including the steps of radiating a suppressed carrier wave with a modulation component of phase depending upon azimuth radiating a carrier wave with two modulation components of constant phases, said three modulation components being of different and harmonically related frequencies, receiving and demodulating said waves, separating said modulation components of different frequencies, changing the frequency of one of said constant phase components to a frequency equal to that of said component of azimuthally dependent phase, comparing said frequency changed component with said constant phase component to provide a unique coarse indication of azimuth, and comparing the other of said constant phase components with said component of azimuthally dependent phase to provide a iine indication of azimuth.
DAVID G. C. LUCK.
REFERENCES CETED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,129,004 Greig Sept. 6, 1938 2,252,699 Byrne Aug. 19, 1941
US460292A 1942-09-30 1942-09-30 Omnidirectional radio range Expired - Lifetime US2422110A (en)

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GB1?097/44A GB594532A (en) 1942-09-30 1944-08-08 Improvement in omnidirectional radio navigation-aiding systems

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Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500793A (en) * 1943-06-12 1950-03-14 Marguerite Lucie Julienne Bour Rotating field radio beacon
US2530600A (en) * 1943-04-12 1950-11-21 Hartford Nat Bank & Trust Co Radio direction finder
US2536509A (en) * 1946-12-24 1951-01-02 Rca Corp Radio aid to navigation
US2551828A (en) * 1944-02-05 1951-05-08 Hartford Nat Bank & Trust Co Radio beacon
US2557855A (en) * 1948-01-26 1951-06-19 Fr Sadir Carpentier Soc Radio guiding system
US2564703A (en) * 1947-10-29 1951-08-21 Sperry Corp Omni-azimuth guidance system
US2565506A (en) * 1949-07-26 1951-08-28 Sperry Corp Omnidirectional radio range system
US2570880A (en) * 1946-05-10 1951-10-09 Gen Electric Co Ltd Radio beacon for aircraft
US2582894A (en) * 1945-07-26 1952-01-15 Williams Frederic Calland Wireless beacon system
US2596537A (en) * 1944-02-04 1952-05-13 Hartford Nat Bank & Trust Co Rotating radio beacon
US2626392A (en) * 1946-02-06 1953-01-20 Decca Record Co Ltd Radio direction indicating system
US2650359A (en) * 1950-03-20 1953-08-25 William W Brockway Radio navigation system
US2713163A (en) * 1951-12-14 1955-07-12 Itt Multilobe omnirange beacon systems
US2715727A (en) * 1951-03-14 1955-08-16 Itt Omnidirectional radio range system
US2753555A (en) * 1951-03-14 1956-07-03 Itt Omni direction radio range system
US2765461A (en) * 1952-08-01 1956-10-02 Alford Andrew Monidirectional range system
US2787787A (en) * 1950-12-01 1957-04-02 Int Standard Electric Corp Receiving arrangements for electric communication systems
US2836814A (en) * 1952-06-25 1958-05-27 Itt R-f phase shifter
DE1069221B (en) * 1959-11-19 International Standard Electric Corporation, New, York, N. Y. (V. St. A.) Radio navigation systems
US3631495A (en) * 1968-05-24 1971-12-28 Univ Sydney Omnidirectional navigation transmission system and apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2129004A (en) * 1937-05-08 1938-09-06 Bell Telephone Labor Inc Radio signaling
US2252699A (en) * 1938-07-30 1941-08-19 Collins Radio Co Azimuth radio beacon system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2129004A (en) * 1937-05-08 1938-09-06 Bell Telephone Labor Inc Radio signaling
US2252699A (en) * 1938-07-30 1941-08-19 Collins Radio Co Azimuth radio beacon system

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1069221B (en) * 1959-11-19 International Standard Electric Corporation, New, York, N. Y. (V. St. A.) Radio navigation systems
US2530600A (en) * 1943-04-12 1950-11-21 Hartford Nat Bank & Trust Co Radio direction finder
US2500793A (en) * 1943-06-12 1950-03-14 Marguerite Lucie Julienne Bour Rotating field radio beacon
US2596537A (en) * 1944-02-04 1952-05-13 Hartford Nat Bank & Trust Co Rotating radio beacon
US2551828A (en) * 1944-02-05 1951-05-08 Hartford Nat Bank & Trust Co Radio beacon
US2582894A (en) * 1945-07-26 1952-01-15 Williams Frederic Calland Wireless beacon system
US2626392A (en) * 1946-02-06 1953-01-20 Decca Record Co Ltd Radio direction indicating system
US2570880A (en) * 1946-05-10 1951-10-09 Gen Electric Co Ltd Radio beacon for aircraft
US2536509A (en) * 1946-12-24 1951-01-02 Rca Corp Radio aid to navigation
US2564703A (en) * 1947-10-29 1951-08-21 Sperry Corp Omni-azimuth guidance system
US2557855A (en) * 1948-01-26 1951-06-19 Fr Sadir Carpentier Soc Radio guiding system
US2565506A (en) * 1949-07-26 1951-08-28 Sperry Corp Omnidirectional radio range system
US2650359A (en) * 1950-03-20 1953-08-25 William W Brockway Radio navigation system
US2787787A (en) * 1950-12-01 1957-04-02 Int Standard Electric Corp Receiving arrangements for electric communication systems
US2715727A (en) * 1951-03-14 1955-08-16 Itt Omnidirectional radio range system
US2753555A (en) * 1951-03-14 1956-07-03 Itt Omni direction radio range system
US2713163A (en) * 1951-12-14 1955-07-12 Itt Multilobe omnirange beacon systems
US2836814A (en) * 1952-06-25 1958-05-27 Itt R-f phase shifter
US2765461A (en) * 1952-08-01 1956-10-02 Alford Andrew Monidirectional range system
US3631495A (en) * 1968-05-24 1971-12-28 Univ Sydney Omnidirectional navigation transmission system and apparatus

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