Patent ID: 7405708

Claim:
An antenna comprising: a main reflector being a body of revolution of an arbitrary curve and having an apex; a sub-reflector being a body of revolution of an arbitrary curve, having a circle and a vertex pointing to the main reflector, being placed between the circle and the main reflector; and a radiator being located along an axis of the revolutions, being placed between the main reflector and the sub-reflector, wherein the ratio of the distance between the circle of the sub-reflector and the apex of the main reflector to the diameter of the main reflector ranges 0.15˜0.35 and the main reflector and the sub-reflector are defined as below: z m ⁡ ( r , D ) = ∑ n = 0 4 ⁢ ∑ m = 0 6 ⁢ qm n , m ⁢ D m - n + 1 ⁢ r n , ⁢ z s ⁢ ( r , D ) = ∑ n = 0 4 ⁢ ∑ m = 0 6 ⁢ qs n , m ⁢ D m - n + 1 ⁢ r n , wherein, z, r are coordinates of the main reflector and the sub-reflector measured in millimeters, Index m corresponds to the main reflector, and index s to the sub-reflector D is the main reflector diameter measured in millimeters, and numbers qm n,m and qs n,m is selected in the ranges as the below: qm ⁢ ⁢ 0 n , m - 3 D m + 1 ≤ qm n , m ≤ qm ⁢ ⁢ 0 n , m + 3 D m + 1 , ⁢ qs ⁢ ⁢ 0 n , m - 1.5 D m + 1 ⁢ 40 n ≤ qs n , m ≤ qs ⁢ ⁢ 0 n , m + 1.5 D m + 1 ⁢ 40 n , where qs0 n,m , qm0 n,m are defined in the below tables: qs0 n,m m = 0 1 2 3 n = 0 0.40362 −0.00422 1.87E−05 −4.3E−08 1 −7.98145 0.098642 −0.00044 1.02E−06 2 −325.922 3.60874 −0.01599 3.54E−05 3 2687.903 −27.1192 0.101879 −0.00017 4 4992.915 −116.572 0.882748 −0.00311 qS0 n,m 4 5 6 n = 0 5.47E−11 −3.6E−14 9.57E−18 1 −1.3E−09 8.36E−13 −2.2E−16 2 −4.2E−08 2.44E−11 −5.6E−15 3 1.02E−07 2.11E−11 −3.2E−14 4 5.53E−06 −4.8E−09 1.65E−12 qm0 n,m m = 0 1 2 3 n = 0 −1.67048 0.017508 −7.9E−05 1.77E−07 1 1.882187 −0.03057 0.000154 −3.8E−07 2 −9.07096 0.118857 −0.00053 1.18E−06 3 0 0 0 0 4 0 0 0 0 qm0 n,m 4 5 6 n = 0 −2.1E−10 1.34E−13 −3.4E−17 1 4.91E−10 −3.3E−13 8.85E−17 2 −1.4E−09 9.02E−13 −2.3E−16 3 0 0 0 4 0 0 0.