HELICOPTER UHF ANTENNA SYSTEM FOR SATELLITE COMMUNICATIONS

• US 3,701,157 A
• Filed: 06/03/1971
• Issued: 10/24/1972
• Est. Priority Date: 06/03/1971
• Status: Expired due to Term

• Current Assignee: Jerome W. Uhrig
• Original Assignee: Jerome W. Uhrig
• Inventors: Uhrig, Jerome W.
• Application Number:
  US05/149,495
• Time in Patent Office: 509 Days
• US Class Current: 343/708
• CPC Class Codes: H01Q 1/282 Modifying the aerodynamic properties of the vehicle, e.g. projecting type aerials
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A UHF antenna comprising crossed dipoles in the shape of drooped bow ties, encased by a polyester fiberglass laminated cone, positioned above and rotating with the blades of the helicopter, and orthogonally fed by a coaxial transmission line running through the hollow rotating mast provides an antenna for overhead signal transmission and reception. A coaxial rotary joint is placed inside the mast at the lower end to make a rotating electrical connection with the feed line.

Claims

1. An antenna system, for a helicopter having a hollow rotor mast, for communicating via overhead satellite link, comprising:

a. dual crossed bow tie radiating elements positioned on the top of the said rotor mast and rotating therewith;

b. means cooperating with the interior of the said hollow mast and rotating therewith for orthogonally feeding the said radiating elements for circularly polarized radiation; and

c. means for electrical coupling from exterior the said mast to the means for orthogonally feeding the radiating elements.

2. An antenna system for communicating with a conventional communication set from a helicopter having a hollow rotor mast via overhead satellite link, the said communication set having a determined connecting impedance comprising:

a. drooped, dual, crossed bow tie antenna radiating elements, quadrature spaced, enclosed in an insulating protective cover;

b. means including a hollow tube cooperating with the said enclosed antenna radiating elements and the said rotor mast for axially positioning the antenna in fixed relationship on top of the rotor mast;

c. means cooperating with the said antenna elements extending into the said hollow tube for orthogonally coupling the said antennA elements and providing a common point of signal coupling;

d. means including an electrical quarter wavelength of coaxial cable for matching the electrical impedance at the said common signal coupling point to provide the said connecting impedance of the communication set, the said matching means being contained within the hollow rotor mast; and

e. means including a coaxial rotary joint positioned at the bottom of the said rotor mast, for coupling the said communication set to the said matching means.