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Publication numberUS3811127 A
Publication typeGrant
Publication dateMay 14, 1974
Filing dateAug 10, 1972
Priority dateAug 10, 1972
Publication numberUS 3811127 A, US 3811127A, US-A-3811127, US3811127 A, US3811127A
InventorsL Griffee, M Anderson
Original AssigneeCollins Radio Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Antenna for airborne satellite communications
US 3811127 A
Abstract
A broadband VHF/UHF antenna exhibiting a hemispherical radiation pattern comprising four orthogonally positioned radiating elements and means for feeding the elements in phase quadrature. Each element includes a vertical blade portion and a capacitive loading section attached to the upper edge of the blade portion. The capacitive loading portions define at least approximately a spherical section.
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Description  (OCR text may contain errors)

United States Patent 1191 Griffee et al.

[ ANTENNA FOR AIRBORNE SATELLITE COMMUNICATIONS [75] Inventors: Leslie V. Griffee, Dallas; Mardis V.

Anderson, Richardson, both of Tex.

[73] Assignee: Collins Radio Company, Dallas,

Tex.

[22] Filed: Aug. 10, 1972 21 Appl. No.2 279,590

[52] U.S. Cl 343/705, 343/770, 343/797, 343/846 51 1111.01. noi l/28 [58] Field of Search 343/770, 771, 895, 705,

[5 6] References Cited UNITED STATES PATENTS 3,366,963 1 1968 Coff ..343/s95 1111 3,811,127 1451 May 14, 1974 3,015,101 12/1961 Turner et al 343/895 3,641,578 2/1972 Spanos et al..... 343/773 3,701,157 10/1972 Uhrig 343/708 Primary ExaminerEli Lieberman [5 7] ABSTRACT A broadband VHF/UHF antenna exhibiting a hemispherical radiation pattern comprising four orthogonally positioned radiating elements and means for feeding the. elements in' phase quadrature. Each element includes a vertical blade portion and a capacitive loading section attached to the upper edge of the blade portion. The capacitive loading portions define at least approximately a spherical section.

6 Claims,.5 Drawing Figures PATENTEDMAY141974 3.81 1,127

SHEET 1 [IF 2 PRIOR ART 1 10.1 FIG. 2

PATENTEB MAY 1 41974 SHEET 2 [IF 2 90 HYBRID ANTENNA FOR AIRBORNE SATELLITE COMMUNICATIONS This invention relates generally to radio antennas, and more particularly to antennas operable in the VHF and UHF ranges for airborne satellite communications.

The use of satellite communication for aircraft applications has become a reality in governmental and commercial use. Typically, such communication requires an aircraft antenna mounted on the upper fuselage, exhibiting a hemispherical coverage pattern, and operable in the VHF and UHF ranges. Conventional antennas are available for such use, but these antennas are limited in frequency bandwidth due to practical design considerations.

Accordingly, an object of the present invention is an improved VHF/UHF airborne antenna.

Another object of the invention is an improved airborne antenna for satellite communication which is operable over a wide frequency range.

Yet anotherobject of the invention is a broadband VHF/UHF airborne antenna for satellite communication which is physically compatible with fuselage mounting.

Features of the invention include a plurality of radiating elements each comprising a vertical member having a generally arcuate upper edge portion and a capacitive loading portion defining at least approximately a spherical section which is attached to said vertical member along the arcuate upper edge. Four of such radiating elements are supportably positioned orthogonally whereby said spherical sections define at least approximately a larger spherical section. Feed means is provided for feeding said radiating element in phase quadrature.

These and other objects and features of the invention will be more readily apparent from the following detailed description and appended claims when taken with the drawing, in which:

FIG. 1 and FIG. 2 illustrate in perspective prior art antennas used for airborne satellite communication;

FIG. 3 is a perspective view of an antenna in accordance with the present invention; 7

FIG. 4 is an exploded view of one radiating element of the antenna of FIG. 3; and

FIG. 5 is a plan view of feed means for phase quadrature exciting the antenna of FIG. 3.

Referring now to the drawing, FIG. 1 and FIG. 2 illustrate in perspective prior art antennas used for airborne satellite communication. FIG. 1 is a turnstile antenna including four orthogonally oriented vertical elements l0, 12, 14, and 1 6 which are supported on support base 18. When fed in phase quadrature, the turnstile antenna exhibits a hemispherical radiation pattern with the radiation emanating from each of the vertical radiating elements. Such an antenna has been satisfactorily employed for relatively narrow bands such as, for example, 240-250 MHz. However, for the turnstile antenna to operate satisfactorily over a broader frequency range, 240-400 MHz, for example, the maximum vertical height for each radiating element must be increased from about five inches to over eight inches. Considering that the antenna must be mounted in the upper fuselage and enclosed by radome, it will be appreciated that such a broadband antenna is too large for satisfactory mounting on the modern jet aircraft.

The prior art crossed-slot antenna of FIG. 2 presents a minimum height profile when mounted to the fuselage of an aircraft, and a hemispherical pattern is generated across the slots between radiating element 20, 22, 24, and 26. However, an operationally satisfactory broadband crossed-slot antenna becomes too large in horizontal displacement for fuselage mounting.

By combining the radiating features of the turnstile antenna and the crossed array antenna, applicant has provided a broadband VHF/UHF antenna which is within the physical constraints necessary for use in airborne satellite communications. Referring to FIG. 3, one embodiment of an antenna in accordance with applicants invention is illustrated in perspective and-includes radiating elements30, 32, 34, and 36 which are orthogonally mounted on base plate 38. These elements are grounded at the outer corners and are shunt fed in phase quadrature approximately halfway toward the center of the antenna by means of a balanced feed system such as,'for example, a combination coaxial cable and stripline.

As seen in the exploded view in FIG. 4, each radiating element comprises a vertical blade portion 40 which is grounded at the external corner 42 and is fed by coaxial means at corner 44, corner 42 being mounted to the support plate 38 of FIG. 3 and corner 44 being attached to metal conductor 68 and of FIG. 5. The upper edge 46 of blade 40 comprises straight lines which together approximate an arcuate curve which receives by welding or other suitable means a capacitive loading portion comprising members 48 and 50. As seen in FIG. 3, the capacitive loading portion comprising elements 48 and 50 define at least approximately a spherical section which is attached to the upper arcuate edge of the vertical blade member and along with the other capacitive loading portions of the radiating elements cooperatively define at least approximately a larger spherical section. While in this illustrative embodiment the spherical sections are approximated by adjoining planar sections, and the illustrative embodiment is satisfactorily operational, true spherical sections may be employed. Arm 52 attached to blade 40 in FIG. 4 functions solely for additional support to the cantilevered capacitive load element .48.

As indicated above, the antenna of FIG. 3 and FIG. 4 when fed in phase quadrature exhibits a hemispherical radiation pattern which is radiated cross the gaps between the radiating elements 32, 34, 36, and 38, as seen in FIG. 3 and emanating outwardly from the vertical blade member 40 as illustrated in FIG-4. Advantageously, the capacitive loading provided by the spherical sections increases the effective height of each blade member without the necessity for physically enlarging the height. This advantage provided by the present invention allows the broadband antenna to be mounted on the upper fuselage of an aircraft within the physical constraints allowed therefor.

The method of exciting the radiating elements in phase quadrature as illustrated in the plan view of FIG. 5 is conventional and well known in the art. An input signal is applied to a hybrid which provides two output signals at 90 phase separation, as shown. Referring to the 0 phase output, coaxial line 60 connects hybrid 62 to a coaxial line positioned on stripline 64 with the outer conductor of coaxial line 64 electrically connected to the metal conductor 68 of the stripline. A like stripline 70 is positioned in alignment with stripline 66 with a gap 72 separating the two striplines. Coaxial line 64 terminates at gap 72 and the center conductor thereof is electrically connected to the metal conductor 74 of stripline 70, thereby causing a 180 phase reversal between the signal in stripline 66 and the signal in stripline 70.

Diametrically opposed blades 78 and 80 are mounted above striplines 66 and 70, respectively, and are electrically interconnected therewith whereby blade 78 is excited at the phase, for example, while blade 80 is energized at 180 phase. It will be noted that blades 78 and 80 contact the two striplines at points 79 and 81 away from gap 72. The exact point at which the blade contacts the stripline is a variable parameter used for impedance matching of the blade to a stripline. Similar striplines, not shown, are employed with the 90 output from hybrid 62 to feed the other pair of radiating elements of the antenna.

An antenna in accordance with the present invention provides hemispherical coverage over a wide frequency range while being compatible with the physical constraints requisite in mounting in the fuselage'of an aircraft. While the invention has been described with reference to a specific embodiment, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A broadband VHF-UHF airborne antenna for satellite communication comprising four radiating elements, a support base, said radiating elements mounted orthogonally on said support base, each of said radiating elements including a vertical member having an upper edge portion and a capacitive loading portion defining at least approximately a spherical section, said capacitive loading portion being attached to said vertical member along said upper edge portion, said capacitive loading portions of said radiating elements cooperatively defining a larger, at least approximately spherical section, and feed means for electrically feeding said upper edge portion, a generally triangularly shaped capacitive loading portion defining at' least a section of a spherical surface, and means for attaching said capacitive loading portion to said vertical member along said upper edge portion.

5. A radiating element as defined in'claim 4 and including feed means attached to said vertical member for energizing said element.

6. A radiating element as defined by claim 4 wherein said upper edge portion is generally arcuate in configuration.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3015101 *Oct 31, 1958Dec 26, 1961Turner Edwin MScimitar antenna
US3366963 *Nov 16, 1964Jan 30, 1968Sperry Rand CorpReduced-height scimitar antenna
US3641578 *Jul 21, 1970Feb 8, 1972IttDiscone antenna
US3701157 *Jun 3, 1971Oct 24, 1972Us Air ForceHelicopter uhf antenna system for satellite communications
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3952310 *Feb 20, 1975Apr 20, 1976Rockwell International CorporationCrossed dipole and slot antenna in pyramid form
US3987458 *Jul 25, 1975Oct 19, 1976The United States Of America As Represented By The Secretary Of The ArmyLow-profile quadrature-plate UHF antenna
US4031539 *Dec 11, 1975Jun 21, 1977Rca CorporationBroadband turnstile antenna
US4475109 *Jan 25, 1982Oct 2, 1984Rockwell International CorporationInflatable antenna
US4675685 *Apr 17, 1984Jun 23, 1987Harris CorporationLow VSWR, flush-mounted, adaptive array antenna
US4847627 *Sep 8, 1987Jul 11, 1989Lockheed CorporationCompact wave antenna system
US4878062 *Jul 28, 1988Oct 31, 1989Dayton-Granger, Inc.Global position satellite antenna
US5068671 *Jun 24, 1988Nov 26, 1991The United States Of America As Representated By The Secretary Of The Air ForceOrthogonally polarized quadraphase electromagnetic radiator
US5406292 *Jun 9, 1993Apr 11, 1995Ball CorporationCrossed-slot antenna having infinite balun feed means
US5614917 *Aug 14, 1995Mar 25, 1997Ford Motor CompanyRF sail pumped tuned antenna
US6356235Sep 20, 1999Mar 12, 2002Motorola, Inc.Ground based antenna assembly
US6499027May 26, 1998Dec 24, 2002Rockwell Collins, Inc.System software architecture for a passenger entertainment system, method and article of manufacture
US6512496Jan 17, 2001Jan 28, 2003Asi Technology CorporationExpandible antenna
US6618016 *Feb 21, 2001Sep 9, 2003Bae Systems Aerospace Inc.Eight-element anti-jam aircraft GPS antennas
US6738026 *Dec 9, 2002May 18, 2004Centurion Wireless Technologies, Inc.Low profile tri-filar, single feed, helical antenna
US6771226 *Jan 7, 2003Aug 3, 2004Northrop Grumman CorporationThree-dimensional wideband antenna
US6782392May 26, 1998Aug 24, 2004Rockwell Collins, Inc.System software architecture for a passenger entertainment system, method and article of manufacture
US6807538May 26, 1998Oct 19, 2004Rockwell CollinsPassenger entertainment system, method and article of manufacture employing object oriented system software
US6813777May 26, 1998Nov 2, 2004Rockwell CollinsTransaction dispatcher for a passenger entertainment system, method and article of manufacture
US6819291Jun 2, 2003Nov 16, 2004Raymond J. LackeyReduced-size GPS antennas for anti-jam adaptive processing
US6938258May 26, 1998Aug 30, 2005Rockwell CollinsMessage processor for a passenger entertainment system, method and article of manufacture
US7028304May 26, 1998Apr 11, 2006Rockwell CollinsVirtual line replaceable unit for a passenger entertainment system, method and article of manufacture
US7450081Mar 12, 2007Nov 11, 2008Sandia CorporationCompact low frequency radio antenna
US7450082Mar 31, 2006Nov 11, 2008Bae Systems Information And Electronics Systems Integration Inc.Small tuned-element GPS antennas for anti-jam adaptive processing
US8106846May 1, 2009Jan 31, 2012Applied Wireless Identifications Group, Inc.Compact circular polarized antenna
US8217850 *Aug 14, 2008Jul 10, 2012Rockwell Collins, Inc.Adjustable beamwidth aviation antenna with directional and omni-directional radiation modes
US8618998Jul 21, 2009Dec 31, 2013Applied Wireless Identifications Group, Inc.Compact circular polarized antenna with cavity for additional devices
US8723731Sep 21, 2009May 13, 2014Topcon Gps, LlcCompact circularly-polarized antenna with expanded frequency bandwidth
US8791872 *Jan 24, 2008Jul 29, 2014Groupe des Ecoles des Telecommunications (ENST Bretange)Ultra wide band antenna or antenna member
US20100103070 *Jan 24, 2008Apr 29, 2010Groupe Des Ecoles Des Telecommunications (Enst BreUltra wide band antenna or antenna member
EP0431764A2 *Nov 12, 1990Jun 12, 1991Trimble NavigationAntenna with curved dipole elements
WO2003058762A1 *Dec 27, 2001Jul 17, 2003Ploussios GeorgeCrossed bent monopole doublets
WO2008102406A2 *Feb 20, 2008Aug 28, 2008Clarbruno VedruccioCircular polarization omnidirectional antenna
WO2010035104A1 *Sep 23, 2009Apr 1, 2010Topcon Gps, LlcCompact circularly-polarized antenna with expanded frequency bandwidth
Classifications
U.S. Classification343/705, 343/770, 343/797, 343/846
International ClassificationH01Q21/26, H01Q9/43, H01Q1/28
Cooperative ClassificationH01Q1/283, H01Q21/26, H01Q9/43
European ClassificationH01Q21/26, H01Q9/43, H01Q1/28C1