Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
In a toroidal reflector antenna system including a main reflector having the shape of a surface section of a toruS of revolution and a feed-horn assembly positioned to illuminate said main reflector and thereby form beams in the desired directions of propogation, the improvement comprising an aberration correcting subreflector interposed between said main reflector and said feed-horn and forming a feed assembly with said feedhorn, the surface of said subreflector being nonconcentric with said main reflector and so designed that for the aberration correcting surface of said subreflector only one ray is incident on the surface at each point thereon, substantially all rays focus at a single point at said feed-horn and substantially all ray pathlengths from a reference aperture plane to said single point of focus are constant and equal to a predetermined reference pathlength, whereby said system is free of aberration and the efficiency of said system is independent of frequency, said feed assembly further being movable along an arc about the axis of revolution of said main reflector to provide substantially aberration free beams in scanning.
Claim 2
Dependent Claim
179 words
In a toroidal reflector antenna system including a main reflector having the shape of a surface section of a toruS of revolution and a feed-horn assembly positioned to illuminate said main reflector and thereby form beams in the desired directions of propogation, the improvement comprising an aberration correcting subreflector interposed between said main reflector and said feed-horn and forming a feed assembly with said feedhorn, the surface of said subreflector being nonconcentric with said main reflector and so designed that for the aberration correcting surface of said subreflector only one ray is incident on the surface at each point thereon, substantially all rays focus at a single point at said feed-horn and substantially all ray pathlengths from a reference aperture plane to said single point of focus are constant and equal to a predetermined reference pathlength, whereby said system is free of aberration and the efficiency of said system is independent of frequency, said feed assembly further being movable along an arc about the axis of revolution of said main reflector to provide substantially aberration free beams in scanning.
Claim 3
Dependent Claim
23 words
The improved antenna system as recited in claim 1 wherein said torus of revolution has a generating curve which is a conic section.
Claim 4
Dependent Claim
16 words
The improved antenna system as recited in claim 2 wherein said generating curve is a parabola.
Claim 5
Dependent Claim
35 words
The improved antenna system as recited in claim 3 wherein said main reflector is a surface section of a nonrectangular torus, said antenna system having a conical scan capability to scan along the geostationary arc.
Claim 6
Dependent Claim
27 words
The improved antenna system as recited in claim 4 wherein the angle between the axis of revolution of said torus and direction of said beam is 95.5*.
Claim 7
Dependent Claim
100 words
The improved antenna system as recited in claim 5 wherein said main reflector has the dimensional ratios f/R about 0.5 and R/D about 2 where f is the focal length of the parabola generating section, R is the radius of revolution, and D is the aperture of said main reflector measured parallel to the axis of revolution and said subreflector is hyperbolic along the axis of symmetry and departs from hyperbolic of the axis of symmetry in such a manner as to preserve the two essential properties of focusing all rays at the desired focal point with the desired pathlength.
Claim 8
Dependent Claim
16 words
The improved antenna system as recited in claim 6 wherein the dimensional ratio f/R < 0.5.
Claim 9
Dependent Claim
70 words
The improved antenna system as recited in claim 6 wherein the dimensional ratio f/R > 0.5 and the vertex of the subreflector is chosen to lie between the projection of the paraxial focus P and the focal point F and the feed point is chosen so that the subreflector formed by a circular pencil of rays incident on the aperture D approximates a circle when viewed from the feed point.
Claim 10
Dependent Claim
80 words
The improved antenna system as recited in claim 8 wherein said main reflector has the dimensional ratios of f/R about 0.56 and R/D about 2 where f is the focal length of the parabola generating section, R is the radius of revolution, and D is the length of said main reflector measured parallel to the axis of revolution, and said subreflector has a cross section which resembles an elliptic section along an axis chosen perpendicular to the axis of symmetry.