Dual mode quadrifilar helix antenna and associated methods of operation
First Claim
1. An antenna system for transmitting electrical signals, comprising:
- a quadrifilar helix antenna having four radiating elements, wherein said quadrifilar helix antenna is configured to operate in a helical radiation mode and a monopole radiation mode;
a phase quadrature antenna feed coupled to said quadrifilar helix antenna for exciting said radiating elements in phase quadrature; and
an in-phase antenna feed, separate from said phase quadrature antenna feed, coupled to said quadrifilar helix antenna for exciting said radiating elements in-phase; and
second matching means coupled to the elements of said quadrifilar helix antenna for matching the impedance of said quadrifilar helix antenna to the impedance of said in-phase antenna feed; and
wherein said quadrifilar helix antenna operates in a helical radiation mode when excited by said phase quadrature antenna feed and operates in a monopole radiation mode when excited by said in-phase antenna feed.
3 Assignments
0 Petitions
Accused Products
Abstract
Antenna systems for transmitting electrical signals are provided which include a quadrifilar helix antenna. A first antenna feed is coupled to the quadrifilar helix antenna for exciting the radiating elements in phase quadrature. A second antenna feed is also coupled to the quadrifilar helix antenna for exciting the radiating elements in-phase. These antenna systems may be operated in either a helical radiation mode, where the antenna may be designed to radiate as a resonant quadrifilar helix antenna, or in a monopole radiation mode, where the antenna acts as the equivalent of a large monopole antenna. Additionally, the antenna systems may further include means for matching the impedance of the quadrifilar helix antenna to the impedance of either or both of the antenna feeds.
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Citations
18 Claims
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1. An antenna system for transmitting electrical signals, comprising:
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a quadrifilar helix antenna having four radiating elements, wherein said quadrifilar helix antenna is configured to operate in a helical radiation mode and a monopole radiation mode; a phase quadrature antenna feed coupled to said quadrifilar helix antenna for exciting said radiating elements in phase quadrature; and an in-phase antenna feed, separate from said phase quadrature antenna feed, coupled to said quadrifilar helix antenna for exciting said radiating elements in-phase; and second matching means coupled to the elements of said quadrifilar helix antenna for matching the impedance of said quadrifilar helix antenna to the impedance of said in-phase antenna feed; and wherein said quadrifilar helix antenna operates in a helical radiation mode when excited by said phase quadrature antenna feed and operates in a monopole radiation mode when excited by said in-phase antenna feed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An antenna system for transmitting electrical signals, comprising:
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a quadrifilar helix antenna having four radiating elements; a first antenna feed coupled to said quadrifilar helix antenna for exciting said radiating elements in phase quadrature; a second antenna feed coupled to said quadrifilar helix antenna for exciting said radiating elements in-phase; and an inductance coupled in series with each of the elements of said quadrifilar helix antenna and a capacitance coupled in parallel with each of the elements of said quadrifilar helix antenna; and wherein said quadrifilar helix antenna operates in a helical radiation mode when excited by said first antenna feed and operates in a monopole radiation mode when excited by said second antenna feed. - View Dependent Claims (11, 12)
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13. An antenna system for transmitting electrical signals in two separate frequency bands, comprising:
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a quadrifilar helix antenna having four radiating elements; a phase quadrature antenna feed coupled to said quadrifilar helix antenna for providing electrical signals in said first frequency band to and from said radiating elements in phase quadrature; an in-phase antenna feed, separate from said quadrature phase antenna feed, coupled to said quadrifilar helix antenna for providing electrical signals in said second frequency band to and from said radiating elements in-phase; a reactive network coupled in shunt to the elements of said quadrifilar helix antenna for matching the impedance of said quadrifilar helix antenna to the impedance of said phase quadrature antenna feed; and second matching means coupled to the elements of said quadrifilar helix antenna for matching the impedance of said quadrifilar helix antenna to the impedance of said in-phase antenna feed. - View Dependent Claims (14, 15, 16)
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17. A method of transmitting electrical signals using an antenna system which includes a quadrifilar helix antenna having four radiating elements and configured to operate in a helical radiation mode and a monopole radiation mode, an in-phase antenna feed coupled to the quadrifilar helix antenna and a phase quadrature antenna feed coupled to the quadrifilar helix antenna, the method comprising the steps of:
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(a) exciting the quadrifilar helix antenna through the phase quadrature antenna feed to operate in a helical radiation mode; (b) exciting the quadrifilar helix antenna through the in-phase antenna feed to operate in a monopole radiation mode; and (c) matching the impedance of the quadrifilar helix antenna to the impedance of the in-phase antenna feed when operating in the monopole radiation mode. - View Dependent Claims (18)
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Specification