US3680119A - Tacan antenna system - Google Patents

Tacan antenna system Download PDF

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Publication number
US3680119A
US3680119A US63877A US3680119DA US3680119A US 3680119 A US3680119 A US 3680119A US 63877 A US63877 A US 63877A US 3680119D A US3680119D A US 3680119DA US 3680119 A US3680119 A US 3680119A
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United States
Prior art keywords
tacan
antennas
spaced relation
signal
disposed
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Expired - Lifetime
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US63877A
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English (en)
Inventor
Svea H Dodington
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TDK Micronas GmbH
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Deutsche ITT Industries GmbH
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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

  • ABSTRACT The nulls and lobes of a Tacan antenna horizontal and/or ver tical radiation patterns 'due to unwanted reflections are reduced by employing two or more Tacan antennas disposed [52] US. Cl. ..343/l06 R, 325/154, 343/100 CS [51] Int. Cl ..G0ls 1/46 m a Predetermmed homomal and/or Vemcal Spaced relanon 53] n w of Search "343/106 R 100 325/154 having each of their radiation patterns rotated synchronously 325/65 and in phase.
  • complete redundancy of transmitter and antenna is provided by having a different 56] References cued transmitter coupled to a different one of the two or more antennas timed to sequentially excite the two or more antennas UNITED STATES PATENTS with a Tacan signal.
  • one transmitter is sequentially coupled to each of the two or more antennas 2,747,181 5/1956 Granqvist ..343/l06 R f sequential excitation thereef by a Tacan SignaL 3,036,30l 5/1962 Wiesner ..343/l00 CS 10 Claims, 5 Drawing Figures '3 l a 5 1* v frf i 7 7 TACAN TA CA N ARRANCIMf/Jf mamw/rrm rRAA/sM/rrm To R0 r4 r5 0 i RADIATION PATTERNS TACA/V SYIVCRONOl/JLY r TRANSMITTER AND m PHASE 15 3 I18 TIM/m: SOURC ,4
  • This invention relates to antenna systems and more particularly to a Tacan antenna system.
  • site-error One of the greatest handicaps of single-site omnidirectional beacons, such as Tacan, is the co-called site-error". This error results from the fact that the vehicle which is trying to determine bearing with respect to the beacon, receives not only the direct, correct signal, but also receives signals which have been reflected from various objects, the most damaging of these reflections are those from objects close to the site of the beacon; hence, the term site-error.
  • An object of the present invention is to provide a Tacan antenna system capable of reducing site error.
  • Another object of the present invention is to provide a Tacan antenna system that does not require specially designed antennas having uptilt.
  • Still another object of the present invention is to provide a Tacan antenna system employing diversity like techniques to reduce the null and lobe structures of both the horizontal and vertical radiation patterns of the Tacan antennas.
  • a feature of the present invention is the provision of a Tacan antenna system comprising a plurality of Tacan antennas disposed in a predetermined spaced relation, each of the plurality of Tacan antennas having a Tacan radiation pattern including nulls and lobes; first means coupled to each of the plurality of Tacan antennas to rotate the radiation pattern of each of the plurality of Tacan antennas synchronously and inphase; and second means coupled to each of the plurality of Tacan antennas to excite each of the Tacan antennas with a Tacan signal; the predetermined spaced relation between the plurality of Tacan antennas being emperically selected to reduce the nulls and lobes in a composite radiation pattern resulting from a combination of the radiation pattern from each of the plurality of Tacan antennas.
  • FIG. 1 is a diagrammatic illustration of a Tacan antenna system and the electrical and/or mechanical components associated therewith to provide the null reduction in accordance with the principles of the present invention
  • FIG. 2 is a curve illustrating the reception of Tacan signals from the antenna system of FIG. 1;
  • FIG. 3 illustrates the vertical radiation patterns generated by the plurality of antennas of FIG. 1 and the composite radiation pattern resulting therefrom;
  • FIG. 4 illustrates diagrammatically another embodiment of the Tacan antenna system in accordance with the principles of the present invention.
  • FIG. 5 illustrates still another embodiment of the Tacan antenna system in accordance with the principles of the present invention.
  • FIG. 1 there is illustrated therein one embodiment of the Tacan antenna system in accordance with the principles of the present invention to compensate for nulls and lobes that are introduced by unwanted reflections in the radiation pattern of a single Tacan antenna, such as by an object I, in the form of a tree, at the antenna site.
  • a single Tacan antenna such as by an object I, in the form of a tree
  • Arrangement 4 may be a pair of synchronized synchronous motors to drive the antenna structure of antennas 2 and 3, or it may be any known arrangement to electronically rotate the antenna patterns to cause the radiation patterns of antennas 2 and 3 to rotate synchronously and inphase.
  • a Tacan signal composed of pairs of pulses, which are amplitude modulated by antenna rotation to provide the bearing information, is provided from Tacan transmitter 5 which through means of electronic switch 6, controlled by the timing source 7, sequentially excites antennas 2 and 3 so as to provide interleaved pulse pairs in each of these antennas whereby the RF pulse pairs are not added, but yet the modulation envelope of these interleaved pulse pairs are added, such as illustrated in FIG. 2 wherein the vertical dash lines 7 indicate pulse pairs from one of the antennas 2 and 3 and the solid vertical lines 8 indicate the pulse pairs from the other of the antennas 2 and 3 with the envelope of the stronger being indicated by line 9.
  • each 15 cycle sine wave is defined by the amplitude of some 200 pairs of pulses, with a duty cycle of about 2 percent. It is, therefore, possible to provide an antenna system wherein each of the antennas is fed by a different pulse or group of pulses, the antennas not being simultaneously energized, and, therefore, not producing unwanted radiation patterns.
  • FIGS. s 1, 2 and 3 have been concerned primarily with the reduction of nulls and lobes in the vertical radiation pattern.
  • This principle can just as well be applied to the horizontal radiation pattern where lobes and nulls may also be caused by unwanted reflections from an object 1 as shown in FIG. 4.
  • three or more Tacan antennas 19, 20 and 21 be disposed in a horizontally spaced relation having a given geometric configuration which is triangular as illustrated in FIG.
  • the present invention may employ multilobe Tacan antennas, simplicity of the antenna system of the present invention is enhanced by employing a plurality of small beacons with single lobe antennas whose bearing outputs at 15 cycles is receivable by all modern Tacan air borne sets. Typical applications are on board aircraft, for rendezvous and station keeping and on the ground for support of tactical operations.
  • the single lobe antennas do not provide as much site freedom as the multilobe designs.
  • a plurality of single lobe antennas might well provide a substantial improvement and, due to each having its own transmitter, would permit a greater total duty cycle as well as reliability improvement due to redundancy.
  • the improvement in horizontal and vertical radiation pattern through the employment of diversity techniques as described hereinabove with respect to FIGS. 1 and 4 is not limited to two or three Tacan antennas, but may be provided by up to or more Tacan antennas with their associated transmitters, each of which are appropriately timed to provide their pulse pairs or groups of pulse pairs in an interleaved arrangement, by a timing source similar to timing source 7.
  • a timing source similar to timing source 7.
  • the horizontal and/or vertical spacing of the antenna arrangements of FIGS. 1, 4 and 5 will depend upon the specific site of the Tacan beacon and, therefore, the spacing both horizontally and/or vertically is determined empirically, since the reflecting objects or object at each site will vary from site to site and, accordingly, the Tacan antenna system must be designed for the particular site in question.
  • a Tacan antenna system comprising: a plurality of Tacan antennas disposed in a predetermined spaced relation, each of said plurality of Tacan antennas having a Tacan radiation pattern including nulls and lobes; first means coupled to each of said plurality of Tacan antennas to rotate said radiation pattern of each of said plurality of Tacan antennas synchronously and inphase; and second means coupled to each of said plurality of Tacan antennas to excite each of said Tacan antennas with a Tacan signal; said predetermined spaced relation being empirically selected to reduce said nulls and lobes in a composite radiation pattern resulting from the combination of said radiation pattern from each of said plurality of Tacan antennas. 2.
  • said second means includes a plurality of sources of said Tacan signal, each of said sources coupled to a different one of said plurality of Tacan antennas, said sources sequentially exciting said plurality of Tacan antennas with said Tacan signal.
  • said second means includes a single source of said Tacan signal, and third means to sequentially couple said source to each of said plurality of Tacan antennas to sequentially excite each of said plurality of Tacan antennas with said Tacan signal.
  • said Tacan signal includes a radio frequency pulse signal amplitude modulated by Tacan reference signals; and said third means causes each of said plurality of Tacan antennas to radiate said radio frequency pulse signal in a sequential relation so that said radio frequency pulse signals do not add while said amplitude modulation envelope does add to maintain said Tacan reference signals.
  • said plurality of Tacan antennas are disposed in a predetermined vertically spaced relation.
  • said plurality of Tacan antennas are disposed in a predetermined horizontal spaced relation and in a given geometric configuration.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
US63877A 1970-08-14 1970-08-14 Tacan antenna system Expired - Lifetime US3680119A (en)

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US6387770A 1970-08-14 1970-08-14

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US3680119A true US3680119A (en) 1972-07-25

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US (1) US3680119A (en(2012))
JP (1) JPS5112514B1 (en(2012))
AU (1) AU456445B2 (en(2012))
DE (1) DE2137556A1 (en(2012))
FR (1) FR2102273B1 (en(2012))
GB (1) GB1329078A (en(2012))

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54123124U (en(2012)) * 1978-02-17 1979-08-28
JPS58118189U (ja) * 1982-02-04 1983-08-12 新日軽株式会社 建具用縦框

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2747181A (en) * 1952-02-23 1956-05-22 Hazeltine Research Inc Radio beacons
US3036301A (en) * 1952-12-05 1962-05-22 Raytheon Co Communication systems

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422076A (en) * 1943-07-28 1947-06-10 Rca Corp Antenna system
US3357018A (en) * 1964-11-06 1967-12-05 Itek Corp Mode-averaging diversity combining reception system for high-frequency radio waves

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2747181A (en) * 1952-02-23 1956-05-22 Hazeltine Research Inc Radio beacons
US3036301A (en) * 1952-12-05 1962-05-22 Raytheon Co Communication systems

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Publication number Publication date
DE2137556A1 (de) 1972-02-17
AU456445B2 (en) 1974-12-19
GB1329078A (en) 1973-09-05
AU3203771A (en) 1973-02-08
FR2102273B1 (en(2012)) 1976-10-29
JPS5112514B1 (en(2012)) 1976-04-20
FR2102273A1 (en(2012)) 1972-04-07

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