WO1991020107A1 - Antenne de lever de doute pour radiogonometrie automatique - Google Patents

Antenne de lever de doute pour radiogonometrie automatique Download PDF

Info

Publication number
WO1991020107A1
WO1991020107A1 PCT/US1990/003186 US9003186W WO9120107A1 WO 1991020107 A1 WO1991020107 A1 WO 1991020107A1 US 9003186 W US9003186 W US 9003186W WO 9120107 A1 WO9120107 A1 WO 9120107A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
metallized
aircraft
antenna element
composite
Prior art date
Application number
PCT/US1990/003186
Other languages
English (en)
Inventor
Gregory Warren Osborne
Leon Hardman
Original Assignee
Bell Helicopter Textron, Inc.
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 Bell Helicopter Textron, Inc. filed Critical Bell Helicopter Textron, Inc.
Priority to PCT/US1990/003186 priority Critical patent/WO1991020107A1/fr
Publication of WO1991020107A1 publication Critical patent/WO1991020107A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H01Q1/286—Adaptation for use in or on aircraft, missiles, satellites, or balloons substantially flush mounted with the skin of the craft
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/29—Combinations of different interacting antenna units for giving a desired directional characteristic

Definitions

  • the present invention relates in general to aircraft radio antenna systems formed in the exterior skin of composite aircraft, and more particularly relates to the integration of an automatic direction finding sense antenna with metallized structures in aircraft of the type employing composite construction airfoils and skins.
  • Direction finding is one of the oldest and most widely used form of navigational aid.
  • the direction of a transmitter with respect to an aircraft may be determined by comparing the arrival time of its transmission at two or more known points. In the simplest practical system, these two points are the vertical arms of a loop antenna connected to a receiver. As the loop is rotated, the received signals cancel each other when the plane of the loop is at right angles to a radial extended to the transmitter station.
  • the major disadvantage of loop antenna direction finding systems is the 180-degree ambiguity problem, wherein the loop antenna can determine the bearing (i.e., the radial along which the transmitter is located), but cannot determine the direction (i.e., whether the transmitter is in front of or behind the receiver) .
  • An Automatic Direction Finder is a device used as an aid to determine the geographical location of the aircraft relative to a ground-based omnidirectional radio transmitter.
  • additional antennas must be used.
  • One such additional or supplemental antenna commonly used is a "sense" antenna.
  • Additional sense antennas can be conveniently attached to the metal surfaces of conventional aircraft to assist in resolving the ambiguity problem.
  • the attachment thereto of radio antennas is more troublesome.
  • conventional antennas cannot be attached to the exterior surface of a composite aircraft without exacting a weight penalty, a wind drag penalty, or other disadvantage.
  • 4,507,341 describes the problems and a solution in attaching the base of an aerial type of radio antenna to a composite fiber-resin type of skin and achieve a low resistance therebetween. It is therefore an objective of the present invention to efficiently and economically provide a sense antenna to be used on composite aircraft which conforms to the shape of the aircraft skin. It is also an object of the present invention to utilize a metallized portion of the composite aircraft as an antenna element for an Automatic Direction Finder navigation receiver.
  • the invention provides for a conformal sense antenna which is embedded or attached to or in the composite skin of an aircraft.
  • a sense antenna is formed.
  • the isolated area interior to the removed part serves as an antenna element for an Automatic Direction Finder navigation receiver.
  • a portion of the metallized composite surface skin can be removed and replaced with another antenna sense element which is shaped so that, when placed and fixed in the opened area in the composite surface skin, a gap of uniform width is formed between the antenna sense element and the perimeter or outer circumference of the metallized composite surface skin.
  • the main body of the composite aircraft serves as a ground plane for the sense antenna system, while the isolated interior portion functions as the sense antenna itself to receive the transmitted signal.
  • the received signal causes the capacitance between the isolated interior antenna element and the exterior metallized portion of the composite surface skin to change. Detected changes in the capacitance are amplified and electrically communicated to an Automatic Direction Finder receiver located in the aircraft. These signals are combined with signals received from a conventional primary loop antenna for determining the bearing and direction of the aircraft with respect to the transmitter station.
  • FIGURE 1 is a perspective view of an aircraft with the sense antenna of the present invention mounted thereunder;
  • FIGURE 2 shows a sense antenna and loop antenna 10 associated with a direction finding receiver
  • FIGURE 3 shows the cardioid pattern resulting from the combination of the sense antenna signal and the loop antenna signal
  • FIGURE 4 illustrates a fragmentary view showing the 15 underside of an aircraft with the sense antenna constructed in accordance with a first embodiment of the present invention
  • FIGURE 5 is a cross-sectional view of the composite aircraft skin, taken along line 5-5 of FIGURE 4; and 20 FIGURE 6 shows a second embodiment of the present invention.
  • ADF Automatic Direction Finder
  • the present invention provides a novel design for sense antennas in composite aircraft wherein a closed- loop strip of metallized material of the composite aircraft is removed to define an interior isolated portion which functions as an antenna element.
  • the use of the isolated metallized area to provide a sense antenna exacts no weight penalty or wind drag penalty, and provides a conforming antenna where conventional antennas would not be feasible.
  • the unique design of the conformal sense antenna of the present invention functions as a supplementary antenna which can be used to resolve the 180 degree ambiguity associated with primary loop antenna detection.
  • FIGURE 1 shows an aerial view of a radio transmitter station 10, defining a navigational aid, and an airplane 12 equipped with the sense antenna 14 of the present invention.
  • the needle pointer of a compass type gauge of the ADF system would point to the north-east (45°) to indicate that the radio navigation station 10 is situated at such a bearing.
  • a sense antenna operating in conjunction with a primary loop antenna of the ADF system such system could not resolve whether the station 10 was located to the north-east or to the south-west.
  • conventional ADF system gauge dials are accurately calibrated in degrees (0-360°) for accurate resolution of the geographical location of the aircraft.
  • FIGURE 2 there is shown a schematic illustration of a well-known rotatable loop antenna 16 and a sense antenna 18 as utilized by a conventional Automatic Direction Finder receiver 20.
  • the loop antenna 16 by itself can provide the bearing to the transmitter 10, but cannot always indicate the direction from which the transmitter 10 is transmitting because of the 180-degree ambiguity problem.
  • Free standing or aerial type of sense antennas 18 are widely used as corrective antenna systems which, when operating in conjunction with a primary loop antenna 16, exhibit a cardioid pattern characteristic 22, as shown in FIGURE 3.
  • the pattern 24 (A and B) for the loop antenna which detects the magnetic field of the transmitted signal, has two nulls 26, which are 180 degrees apart. As the loop antenna 16 is rotated, the received signals cancel each other when the plane of the loop 16 is at a right angle to a radial extending to the transmitting station 10.
  • the pattern C associated with the sense antenna 18 is identified with reference numeral 28. Although the use of a sense antenna 18 to resolve this 180-degree ambiguity is widely known in the art, the particular design of the present invention provides a novel conformal sense antenna especially well adapted for use with composite aircraft skins. As shown in FIGURE 3, the patterns from the sense antenna 18 and loop antenna 16 can be combined to achieve the cardioid pattern 22, by adding pattern B and pattern C, and then subtracting pattern A (which is 180-degrees out of phase with patterns B and C) .
  • the resulting cardioid pattern 22 can be used to determine not only the bearing but also the exact direction of the transmitter 10 with respect to the aircraft 12.
  • the utilization of the ADF sense antenna of the invention is well adapted for use with composite skin type of aircraft. Indeed, the sense antenna of the invention can be efficiently incorporated with lightning protection equipment, and especially the type conductive screen or foil employed with composite skin aircraft structures.
  • FIGURE 4 where there is illustrated a lightning protection screen 30 which is embedded within the skin 32 of a composite aircraft structure.
  • the screen 30 functions as a conductor to carry away or dissipate energy and thus protect the aircraft during lightning strikes.
  • the construction of such a screen in a composite skin structure is well known in the art and need not be further detailed here.
  • the lightning conductor material 30 is generally a sheet material formed or fastened to the exterior surface of the composite superstructure. Resin bonded carbon fibers comprise a well-known type of composite aircraft skin.
  • the sense antenna input of the Automatic Direction Finder is electrically connected to an isolated inner screen portion 38, while the "ground” or common input of the ADF receiver is electrically connected to the metallized outer screen portion 30 which provides the
  • conducting wires or cables are connected to the sense antenna by running wires from the ADF through the exterior skin of the aircraft.
  • a coaxial or similar type of cable 40 can be utilized.
  • 10 cable 40 is connected to the major part of the screening 30, while the inner conductor 44 is connected to the sense antenna 38.
  • the conductors 42 and 44 are preferably soldered or welded to the respective screening conductors 30 and 38. Alternatively, electrical
  • connections can be made to the screen material in a manner similar to that described in U.S. Pat No. 4,507,341.
  • the sense antenna 38 can be located at a convenient location of the aircraft body or
  • FIGURES 4 and 5 illustrate the
  • a sense antenna 38 of a first embodiment of the present invention in which a two-inch rectangular closed-loop strip 34 is removed from the lightning strike screening 30. While a rectangular shaped sense antenna is illustrated, different shapes can be obtained by removing a correspondingly shaped closed-loop strip of the screening material. In any event, by removing a border strip 34 of the screening 30, a rectangular-shaped inner portion 38 remains, which inner portion is electrically isolated from the outer part of the lightning strike screening 30. After severing the screening to form the inner portion 38, the loose ends of the screening material can be epoxied or bonded so that the leading edges of the screening do not separate from the composite superstructure during high speed flight. Preferably, the entire area is resealed to provide an aerodynamically smooth surface.
  • the isolated inner portion 38 After removal of the two-inch rectangular strip 34 which has an inner circumference and an outer circumference, the isolated inner portion 38 defines a sense antenna structure which conforms to the shape of the aircraft and which does not exact a weight penalty or wind drag penalty.
  • the sense antenna function of the isolated inner portion 38 can be combined in function with the lightning protection systems typically employed in composite airframes.
  • the two-inch strip 34 defines an isolating gap which is sufficiently narrow to provide a spark gap so that lightning protection is not degraded. With a gap 34 of no more than about two inches, lightning strikes to the inner portion 38 can be conducted across the gap 34 and be safely carried away or dissipated by the surrounding screening 30 and other components associated with the lightning protection system.
  • the function of the lightning protection system is not compromised, and in addition the conductive screening material provides sense antenna functions for the ADF system.
  • FIGURE 6 depicts a second embodiment of the present invention wherein a portion of the metallized screen 46 of the exterior composite surface skin 48 is entirely removed from the aircraft to form an entire interior opening 50.
  • a sense antenna element 52 of the same or different conductive material is then bonded or otherwise fixed in the opening 50.
  • the sense antenna has a defined circumference depending upon the size of the opened area 50 and the width of the gap 54. Again, a gap 54 or electrically insulated strip of about two inches peripherally borders the sense antenna element 52.
  • the thickness of the sense antenna element 52 is preferably about the same as the thickness of the removed portion so that when fixed in the opening 50, the sense antenna element 52 closely conforms to the surface shape of the aircraft.
  • the sense antenna element 52 can be formed of any suitable conductive material, such as aluminum wire mesh or foil.
  • uniformity of gap width or slot width is of importance in that the sense antenna of the present invention operates as an electronic field antenna, as opposed to a loop antenna which operates as a magnetic field antenna.
  • the electronic field of the transmitter signal is detected by the sense antenna as a function of the capacitance between the isolated inner portion/sense antenna element and the remainder of the metallized composite aircraft skin.
  • the isolated sense antenna element 38 is formed so as to define a rectangular element having dimensions of about 45.0 inches long by about 13.5 inches wide, and an outer circumference (i.e., the perimeter of the opening) having dimensions of about 49.0 inches long by about 17.5 inches wide.
  • a surface- conforming sense antenna for use with an Automatic Direction Finder navigation receiver which is embedded in or disposed on the "skin" of a composite aircraft.
  • the invention utilizes a portion of the lightning protection material of the composite aircraft and thus additional material is not required.
  • an antenna sense element of suitable material such as aluminum mesh, is bonded within an opened area formed within the lightning protection screening.
  • the isolated screen portion, or sense antenna element is isolated from the remainder of the lightning protection material by a spark gap *
  • the isolated area provides a sense antenna which closely conforms to the shape of the airframe and assists in the resolution of the 180-degree ambiguity from the loop antenna detection of a transmitted signal, but does not exact a weight penalty because the antenna can be combined in function with the lightning protection system required in composite aircraft.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Details Of Aerials (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

Une antenne (52) de lever de doute circulaire se conformant à la surface est intégrée à la surface du fuselage (48) d'un avion par enlèvement d'une bande rectangulaire bouclée d'une surface composite extérieure métallisée. La partie métallisée intérieure restante (52) isolée de la section métallisée extérieure (46) forme un élément de détection d'antenne. La partie métallisée interne (52) est connectée à un récepteur de radiogonométrie automatique pour fonctionner comme une antenne de lever de doute à diagramme circulaire en conjonction avec une antenne-cadre. L'espace (50) entre la partie interne métallisée de la section extérieure métallisée permet à l'énergie des éclairs d'être déchargée à ce niveau. Cette modification n'impose pas un handicap pondéral ou un handicap de résistance au vent et ne diminue pas la protection contre les éclairs de l'avion composite.
PCT/US1990/003186 1990-06-12 1990-06-12 Antenne de lever de doute pour radiogonometrie automatique WO1991020107A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US1990/003186 WO1991020107A1 (fr) 1990-06-12 1990-06-12 Antenne de lever de doute pour radiogonometrie automatique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1990/003186 WO1991020107A1 (fr) 1990-06-12 1990-06-12 Antenne de lever de doute pour radiogonometrie automatique

Publications (1)

Publication Number Publication Date
WO1991020107A1 true WO1991020107A1 (fr) 1991-12-26

Family

ID=22220901

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1990/003186 WO1991020107A1 (fr) 1990-06-12 1990-06-12 Antenne de lever de doute pour radiogonometrie automatique

Country Status (1)

Country Link
WO (1) WO1991020107A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6175336B1 (en) 1999-12-27 2001-01-16 Northrop Grumman Corporation Structural endcap antenna
US6198445B1 (en) 1999-12-29 2001-03-06 Northrop Grumman Corporation Conformal load bearing antenna structure
EP2546924B1 (fr) 2011-07-15 2017-02-15 The Boeing Company Système d'antenne intégré
FR3054934A1 (fr) * 2016-08-03 2018-02-09 Airbus Operations Systeme d'emission et/ou de reception d'ondes electromagnetiques embarque dans un aeronef

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2414266A (en) * 1942-06-27 1947-01-14 Rca Corp Antenna
US2636987A (en) * 1953-04-28
US2845624A (en) * 1953-05-08 1958-07-29 Int Standard Electric Corp Low drag airplane antenna
US4507341A (en) * 1983-02-24 1985-03-26 Westland Plc Carbon fibre structures

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636987A (en) * 1953-04-28
US2414266A (en) * 1942-06-27 1947-01-14 Rca Corp Antenna
US2845624A (en) * 1953-05-08 1958-07-29 Int Standard Electric Corp Low drag airplane antenna
US4507341A (en) * 1983-02-24 1985-03-26 Westland Plc Carbon fibre structures

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6175336B1 (en) 1999-12-27 2001-01-16 Northrop Grumman Corporation Structural endcap antenna
US6198445B1 (en) 1999-12-29 2001-03-06 Northrop Grumman Corporation Conformal load bearing antenna structure
EP2546924B1 (fr) 2011-07-15 2017-02-15 The Boeing Company Système d'antenne intégré
FR3054934A1 (fr) * 2016-08-03 2018-02-09 Airbus Operations Systeme d'emission et/ou de reception d'ondes electromagnetiques embarque dans un aeronef
US10205228B2 (en) 2016-08-03 2019-02-12 Airbus Operations (S.A.S.) System for emitting and/or receiving electromagnetic waves embedded in an aircraft

Similar Documents

Publication Publication Date Title
US5353038A (en) Automatic direction finder sense antenna
US6417810B1 (en) Antenna arrangement in motor vehicles
US6653980B2 (en) Antenna for transmission / reception of radio frequency waves and an aircraft using such an antenna
CN105292471B (zh) 一种太阳能电力线路检测无人机
GB719526A (en) Magnetic antenna systems
EP0373604B1 (fr) Système d'antennes avec poursuite de direction
CN105292470B (zh) 一种电力线路检测无人机
CN102084567A (zh) 电子单元的雷电防护装置
CN105235907B (zh) 设有热源检测器的电力线路检测无人机
CN105329440B (zh) 太阳能电力线路检测无人机
US5036323A (en) Active radar stealth device
WO1991020107A1 (fr) Antenne de lever de doute pour radiogonometrie automatique
US3906507A (en) Combination glideslope/localizer antenna for aircraft
US5497167A (en) Antenna for mounting on a vehicle window
US4091386A (en) Rear window direction finding antenna
JPH0254909B2 (fr)
CN103872453A (zh) 用于天线罩的避雷系统以及相关联的组装方法
CN112103626A (zh) 渐缩壁罩
CN105253302B (zh) 一种设有存储装置的电力线路检测无人机
EP3022800B1 (fr) Système et procédé de montage d'une antenne radiogoniométrique dans un radôme, de préférence de montage ultérieur dans un radôme existant
US7170467B1 (en) Antenna couplers and method of production
USRE25417E (en) Lightning arrestor for radomes
CN210180456U (zh) 一种用于机载无线电导航的多模式组合接收装置
JPH03220802A (ja) マイクロストリップアンテナ
US6313810B1 (en) Arrangement relating to antenna protection

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU BR CA JP KR NO US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB IT LU NL SE

NENP Non-entry into the national phase

Ref country code: CA