Dual frequency reflector antenna feed element
First Claim
1. A dual frequency feed element for a parabolic reflector antenna system, comprising:
- a) a conductive cavity having a central axis, said cavity for mounting at the focal point of a parabolic reflector surface and defined about its outer perimeter by an upstanding conductive cavity wall, and having a closed conductive cavity floor and an open top for directing toward the reflector surface;
b) a single dual frequency radiating element centrally disposed in said cavity and arranged to radiate a first low frequency signal and a second, higher frequency signal out through said cavity open top to the antenna surface;
c) said conductive floor fixed below said radiating element a distance in relation to the radiant energy for said first low frequency signal, and disposed in said cavity transverse to said central axis to reflect radiant energy for said first signal; and
,d) a frequency selective surface fixed below said radiating element, apart from said conductive cavity floor, and transverse to said central axis of said cavity to reflect radiant energy for said second, higher frequency signal while simultaneously being invisible to said low frequency signal.
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Accused Products
Abstract
A dual frequency feed element for a parabolic reflector antenna system, comprising a conductive cavity having a central axis, the cavity mounted at the focal point of a parabolic reflector surface and defined about its outer perimeter by an upstanding cavity wall, and having a closed cavity floor and an open top directed toward the reflective surface, a dual frequency radiating element centrally disposed in the cavity and arranged to radiate a first low frequency signal out through the cavity open top to the antenna surface, a conductive floor fixed below the radiating element a distance in relation to the radiant energy for the first low frequency signal, and disposed in the cavity transverse to the central axis thereof to reflect radiant energy for the first signal and, a frequency selective surface fixed below the radiating element, apart from the conductive floor, and transverse to the central axis of the cavity to reflect radiant energy for the second, higher frequency signal while simultaneously being invisible to the lower frequency signal.
73 Citations
19 Claims
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1. A dual frequency feed element for a parabolic reflector antenna system, comprising:
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a) a conductive cavity having a central axis, said cavity for mounting at the focal point of a parabolic reflector surface and defined about its outer perimeter by an upstanding conductive cavity wall, and having a closed conductive cavity floor and an open top for directing toward the reflector surface; b) a single dual frequency radiating element centrally disposed in said cavity and arranged to radiate a first low frequency signal and a second, higher frequency signal out through said cavity open top to the antenna surface; c) said conductive floor fixed below said radiating element a distance in relation to the radiant energy for said first low frequency signal, and disposed in said cavity transverse to said central axis to reflect radiant energy for said first signal; and
,d) a frequency selective surface fixed below said radiating element, apart from said conductive cavity floor, and transverse to said central axis of said cavity to reflect radiant energy for said second, higher frequency signal while simultaneously being invisible to said low frequency signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A dual frequency feed element for a parabolic reflector antenna system, comprising:
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a) a conductive cavity having a central axis, said cavity mounted at the focal point of a parabolic reflector surface and defined by its outer perimeter by an upstanding cavity wall and having a closed conductive cavity floor and an open top that is directed toward the reflector surface; b) a single dual frequency radiating element centrally disposed in said cavity and arranged to radiate a first low frequency signal and a second, higher frequency signal out through said cavity open top to the antenna surface; c) a conductive cavity floor fixed below said radiating element a distance in relation to the radiant energy for said first low frequency signal, and disposed in said cavity transverse to said central axis thereof to reflect radiant energy for said first signal; d) a first frequency selective surface fixed below said radiating element, apart from said conductive cavity floor, and transverse to said central axis of said cavity to reflect radiant energy for said second, higher frequency signal while simultaneously being invisible to said lower frequency; and
,e) a second frequency selective surface, forming an upstanding cavity wall above said first frequency selective surface, surrounding said radiating element and interior said cavity wall, invisible to said second high frequency signal and conductive to said first low frequency signal.
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19. A dual frequency feed element for aparabolic reflector antenna system, comprising:
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a) a conductive cavity having a central axis, said cavity mounted at the focal point of a parabolic reflector surface and defined by an outer perimeter and having a closed, conductive cavity floor and an open top that is directed toward the reflector surface; b) a single, dual frequency radiating element centrally disposed in said cavity and arranged to radiate a first low frequency signal and a second, higher frequency signal out through said cavity open top to the antenna surface; c) said cavity floor fixed below said radiating element a distance in relation to the radiant energy for said first low frequency signal, and disposed in said cavity transverse to said central axis thereof to reflect radiant energy for said first signal; d) a first frequency selective surface fixed below said radiating element, apart from said conductive cavity floor, and transverse to said central axis of said cavity to reflect radiant energy for said second, higher frequency signal while simultaneously being invisible to said lower frequency; e) a second frequency selective surface, forming an upstanding wall above said first frequency selective surface, surrounding said radiating element and interior of said outer cavity perimeter, invisible to said second high frequency signal and conductive to said first low frequency signal; f) a third frequency selective surface, forming the cavity wall extending between said cavity perimeter and said first frequency selective surface, invisible to said second high frequency signal and conductive to said first low frequency signal; and g) a conductive cavity wall extending between said third frequency selective surface and said first frequency selective surface.
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Specification