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US 2010/0164834 A1Published application
Dielectrically loaded antenna and an antenna assembly
AssigneeSarantel Limited
InventorOliver Paul Leisten
Life of this patent
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AssigneeSarantel Limited
InventorOliver Paul Leisten
Estimating the term…
A dielectrically loaded quadrifilar helical antenna has four quarter turn helical elements centred on a common axis. Each helical element is metallised on the outer cylindrical surface of a solid dielectric core and each has a feed end and a linked end, the linked ends being connected together by a linking conductor encircling the core. At an operating frequency of the antenna the helical elements and the linking conductor together form two conductive loops each having an electrical length in the region of (2n−1)/2 times the wavelength, where n is an integer. Such an antenna tends to present a source impedance of at least 500 ohms to receiver circuitry to which it is connected. The invention includes an antenna assembly including a dielectrically antenna and a receiver having a radio frequency front-end stage with a differential input coupled to the feed ends of the helical elements.
An antenna assembly comprising a dielectrically loaded multifilar antenna for operation at a frequency in excess of 200 MHz, the antenna having a dielectric core of a solid material having a relative dielectric constant greater than 5, an antenna element structure disposed on or adjacent the outer surface of the core, wherein the antenna assembly further comprises a feed structure having a transversely oriented circuit board mounted on or adjacent an end face of said core and having a differential circuit element disposed thereon, said differential circuit element being coupled to said antenna element structure.
An antenna assembly comprising a dielectrically loaded quadrifilar helical antenna for operation at a frequency in excess of 200 MHz, the antenna having a dielectric core of a solid material having a relative dielectric constant greater than 5, an antenna element structure disposed on or adjacent the outer surface of the core, wherein the antenna assembly further comprises a feed structure having a transversely oriented circuit board mounted on or adjacent a proximal end face of said core and having a differential circuit element disposed thereon, said differential circuit element being coupled to said antenna element structure, wherein said antenna element structure includes a plurality of substantially helical antenna elements and each of said antenna elements is coupled to a circumferentially extending conductor arrangement at a distal end of said core.
Dependencies are inferred from the claim text.