Patent ID: 7158093

Claim:
A quadri-filar helix antenna, comprising: a cylindrical body, being made of a dielectric material with a relative dielectric constant ∈ r greater than 4 , and a penetrating hole disposed at its central position; four radiating metal plates, and an end of said each radiating metal plate being disposed at an end surface of said cylindrical body and extended along the radial direction from the center of said cylindrical body to the periphery of said cylindrical body and then extended in a spiral course along the axial direction from the circumferential surface of said cylindrical body to the periphery at another end of said cylindrical body, and the facing ends of every two adjacent radiating metal plates disposed on one end surface of said cylindrical body being coupled with each other to constitute two sets of antenna structures; a coaxial cable including an insulator, an electrically conductive shield layer covering said outer surface of the insulator, and a feeder conductor disposed at a central position within said insulator, said coaxial cable including said insulator, electrically conductive shield layer and said feeder conductor being embedded in said penetrating hole of the cylindrical body and both facing ends of said sets of antenna structures being protruded from both ends of said penetrating hole and one end of said electrically conductive shield layer being coupled to one end of one said set of antenna structures and one end of said feeder conductor being coupled to one end of another said set of antenna structures.