Dielectrically-loaded antenna
AssigneeSarantel Limited
InventorOliver Paul Leisten
Life of this patent
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Abstract
A dielectrically-loaded helical antenna has a cylindrical ceramic core bearing metallised helical antenna elements which are coupled to a coaxial feeder structure passing axially through the core. Secured to an end face of the core is a circular laminate board having feedthrough holes for receiving the end portions of feeder structure conductors. Coupling conductors on the face of the board that faces the core extend radially outwardly from connections with the feeder structure conductors to plated edge portions of the board. The board is of a diameter substantially equal to that of the core and bridging conductors overlying the plated edge portions connect the coupling conductors to the helical elements. The board incorporates a matching network.
Claims12
A dielectrically-loaded antenna for operation at frequencies in excess of 200 MHz comprising:
- an electrically insulative core of a solid material having a relative dielectric constant greater than 5 and having transversely extending first and second end surfaces and a side surface which extends longitudinally between the end surfaces, the side and end surfaces of the core defining an interior volume the major part of which is occupied by the said solid material;
- a three-dimensional antenna element structure including at least a pair of elongate conductive antenna elements disposed on the side surface of the core and extending from the first end surface towards the second end surface;
- a laminate board on the first end surface of the core in face-to-face juxtaposition therewith and extending to the periphery of the first end surface;
- and a feed connection comprising a pair of feed terminations on the board;
- the laminate board including coupling conductors on the face of the board that faces the core, the coupling conductors coupling the feed terminations to the elongate antenna elements at the periphery of the first end surface of the core.
A dielectrically-loaded antenna for operation at frequencies in excess of 200 MHz comprising:
- an electrically insulative core of a solid material having a relative dielectric constant greater than 5 and having transversely extending first and second end surfaces and a side surface which extends longitudinally between the end surfaces, the side and end surfaces of the core defining an interior volume the major part of which is occupied by the said solid material;
- a three-dimensional antenna element structure including at least a pair of elongate conductive antenna elements disposed on the side surface of the core and extending from the first end surfaces towards the second end surface;
- a laminate board on the first end surface of the core in face-to-face juxtaposition therewith and extending to the periphery of the first end surface;
- and a feed connection comprising a pair of feed terminations on the board;
- the laminate board includes coupling conductors formed as a layer or layers of the board, the coupling conductors coupling the feed terminations to the elongate antenna elements at the periphery of the first end surface of the core;
- and wherein the laminate board further includes plated edge portions that are electrically continuous with the coupling conductors and in registry with end portions of the elongate antenna elements at the said core end surface periphery;
- the antenna further comprising bridging conductors overlying and conductively bonded to the plated edge portions and the antenna element end portions to form the connections between the coupling conductors and the elongate antenna elements.
An antenna constructed and arranged substantially as herein described and shown in the drawings.
Dependencies are inferred from the claim text.