Antenna system for dual mode satellite/cellular portable phone
First Claim
1. An antenna operable in two disparate frequency bands, comprising:
- (a) a first quadrifilar helix including four conductive elements arranged helically to define a cylinder of substantially constant radius, said first quadrifilar helix being formed of two bifilar helices arranged orthogonally and excited in phase quadrature; and
(b) a quadrature feed network connected to said first quadrifilar helix, wherein one end of a coupling element thereof is connected to a first end of each said conductive element, said quadrature feed network further comprising;
(1) a first feedpoint connected to a first pair of said conductive elements, said coupling element being balanced and said first quadrifilar helix having circular polarization, wherein said antenna is operable in a first frequency band; and
(2) a second feedpoint connected to a second pair of said conductive elements, said coupling element being unbalanced and said first quadrifilar helix having linear polarization, wherein said antenna is operable in a second frequency band.
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Accused Products
Abstract
An antenna operable in two disparate frequency bands is disclosed as including a first quadrifilar helix having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the first quadrifilar helix is formed of two bifilar helices arranged orthogonally and excited in phase quadrature. A quadrature feed network is connected to the first quadrifilar helix, wherein one end of a coupling element thereof is connected to a first end of each conductive element. The quadrature feed network also includes a first feedpoint for operation of the antenna with circular polarization in a first frequency band and a second feedpoint for operation of the antenna with linear polarization in a second frequency band. The antenna may include a second quadrifilar helix connected to the quadrature feed network and having four conductive elements arranged helically to define a cylinder of substantially constant radius, where the second quadrifilar helix is formed by two bifilar helices arranged orthogonally and excited in phase quadrature. The second quadrifilar helix is wound in opposite sense with respect to the first quadrifilar helix so as to be conductively coupled therewith.
54 Citations
72 Claims
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1. An antenna operable in two disparate frequency bands, comprising:
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(a) a first quadrifilar helix including four conductive elements arranged helically to define a cylinder of substantially constant radius, said first quadrifilar helix being formed of two bifilar helices arranged orthogonally and excited in phase quadrature; and (b) a quadrature feed network connected to said first quadrifilar helix, wherein one end of a coupling element thereof is connected to a first end of each said conductive element, said quadrature feed network further comprising; (1) a first feedpoint connected to a first pair of said conductive elements, said coupling element being balanced and said first quadrifilar helix having circular polarization, wherein said antenna is operable in a first frequency band; and (2) a second feedpoint connected to a second pair of said conductive elements, said coupling element being unbalanced and said first quadrifilar helix having linear polarization, wherein said antenna is operable in a second frequency band. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. An antenna for transmitting and receiving signals within a first frequency band and a second frequency band, comprising:
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(a) a flexible sheet of film having a first side and a second side; (b) a first metallized pattern formed on said first side of said film sheet including a plurality of spiral arms connected to a coupler; and (c) a second metallized pattern formed on said second side of said film sheet including a plurality of spiral arms connected to a coupler; wherein said film sheet is formed into a cylindrical tube having a longitudinal axis therethrough so that a first coaxial quadrifilar helix is constructed by said spiral arms of said first metallized pattern and a second coaxial quadrifilar helix is constructed by said spiral arms of said second metallized pattern, said first and second quadrifilar helices being wound in opposite directions with respect to said longitudinal axis to avoid electromagnetic coupling therebetween. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. In a portable phone having RF circuitry contained within a main housing for operating said portable phone in both cellular and satellite modes, an antenna assembly comprising:
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(a) a base member connected to a top portion of said portable phone main housing; and (b) a radome member rotatably connected to said base member, said radome member containing a printed antenna therein which is able to transmit and receive signals in said cellular and satellite modes of operation. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)
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68. A quadrifilar helix antenna, comprising:
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(a) a flexible sheet of dielectric film; (b) a first pair and a second pair of conductive arms printed upon said flexible sheet of dielectric film in such manner that said conductive arms form a quadrifilar helix when said flexible sheet is rolled into a cylindrical tube; and (c) a balanced 90°
branch line coupler printed on said flexible sheet of dielectric film, wherein said coupler is able to provide two balanced output signals in phase quadrature relative to each other, said coupler further comprising;(1) a first output port connected to said first pair of conductive arms, said first output port having a first terminal for providing an in-phase portion of a first output signal to one of said first pair of conductive arms and a second terminal for providing an anti-phase portion of said first output signal to the other of said first pair of conductive arms; (2) a second output port connected to said second pair of conductive arms, said second output port having a first terminal for providing an in-phase portion of a second output signal to one of said second pair of conductive arms and a second terminal for providing an anti-phase portion of said second output signal to the other of said second pair of conductive arms; and (3) at least one input port for receiving an input signal and splitting said input signal between said first and second pairs of conductive arms in relative phase progression so as to be radiated with circular wave polarization. - View Dependent Claims (69, 70, 71, 72)
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Specification