Multifilar antenna
First Claim
1. A dielectrically loaded multifilar antenna for circularly polarised radiation the antenna having a plurality of operating frequencies in excess of 200 MHz, wherein the antenna comprises:
- an electrically insulative core having proximal and distal surface portions and, between the proximal and distal surface portions, a laterally directed side surface portion;
a pair of feed nodes;
at least four elongate generally helical conductive radiating elements located on the core; and
, arranged between and coupling together the feed nodes and the radiating elements, a phasing ring formed by a closed loop which is resonant at least one of the operating frequencies, the radiating elements being coupled to the phasing ring at respective spaced apart coupling locations;
the antenna further comprising a conductive linking element extending around the core side surface portion, wherein the radiating elements comprise a first group of elements extending from the phasing ring over the core side surface portion to closed-circuit terminations on the linking element and a second group of elements extending from the phasing ring to open-circuit terminations on the said side surface portion which are spaced from the linking element, and wherein each of the elements of one of said groups is meandered about a respective pure helix.
2 Assignments
0 Petitions
Accused Products
Abstract
Disclosed herein are example embodiments of a dielectrically loaded multifilar antenna for circularly polarised radiation the antenna having a plurality of operating frequencies in excess of 200 MHz. In one embodiment, the antenna comprises: an electrically insulative core having proximal and distal surface portions and, between the proximal and distal surface portions, a laterally directed side surface portion; a pair of feed nodes; at least four elongate generally helical conductive radiating elements located on the core; and, arranged between and coupling together the feed nodes and the radiating elements, a phasing ring formed by a closed loop, wherein the phasing ring is resonant at least two of the operating frequencies, the elongate antenna elements being coupled to the phasing ring at respective spaced apart coupling locations and extending from the phasing ring in a direction away from the feed nodes.
31 Citations
29 Claims
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1. A dielectrically loaded multifilar antenna for circularly polarised radiation the antenna having a plurality of operating frequencies in excess of 200 MHz, wherein the antenna comprises:
an electrically insulative core having proximal and distal surface portions and, between the proximal and distal surface portions, a laterally directed side surface portion;
a pair of feed nodes;
at least four elongate generally helical conductive radiating elements located on the core; and
, arranged between and coupling together the feed nodes and the radiating elements, a phasing ring formed by a closed loop which is resonant at least one of the operating frequencies, the radiating elements being coupled to the phasing ring at respective spaced apart coupling locations;
the antenna further comprising a conductive linking element extending around the core side surface portion, wherein the radiating elements comprise a first group of elements extending from the phasing ring over the core side surface portion to closed-circuit terminations on the linking element and a second group of elements extending from the phasing ring to open-circuit terminations on the said side surface portion which are spaced from the linking element, and wherein each of the elements of one of said groups is meandered about a respective pure helix.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A dielectrically loaded multifilar antenna for circularly polarised radiation having a plurality of operating frequencies in excess of 200 MHz, wherein the antenna comprises:
- an electrically insulative core having proximal and distal surface portions and, between the proximal and distal surface portions, a laterally directed side surface portion;
a pair of feed nodes;
at least four elongate generally helical conductive radiating elements located on the core; and
, arranged between and coupling together the feed nodes and the radiating elements, a phasing ring formed by a closed loop, wherein the phasing ring is resonant at least two of the operating frequencies, the elongate antenna elements being coupled to the phasing ring at respective spaced apart coupling locations and extending from the phasing ring in a direction away from the feed nodes, wherein the phasing ring comprises a conductive track and the phasing ring is formed such that an outer edge of the conductive track resonates at a first frequency of said plurality of operating frequencies, and an inner edge of the conductive track resonates at a second frequency of said plurality of operating frequencies. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
- an electrically insulative core having proximal and distal surface portions and, between the proximal and distal surface portions, a laterally directed side surface portion;
Specification