Low profiled antenna

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 elliptical curve, having a circle and a vertex pointing to the main reflector and, being placed between the circle and the main reflector, and having two focuses, the two focuses being located between the sub-reflector and the main reflector;
• and
• a radiator being located along an axis of revolutions, being placed between the main reflector and the sub-reflector;
• and wherein the sub-reflector has eccentricity ranging from 0.55 to 0.75, and 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.

An antenna comprising:

• a main reflector being a body of revolution of a parabolic shape and having an apex;
• a sub-reflector being a body of revolution of an elliptic shape, having a circle and a vertex pointing to the main reflector, being placed between the circle and the main reflector, and having two focuses including a first focus and a second focus, the two focuses being located between the sub-reflector and the main reflector, the second focus being a focal ring placed away from an axis for the revolution of the elliptic shape;
• and a radiator being located along an axis of the revolutions between the main reflector and the sub-reflector, wherein the relation between the radius of the focal ring of the sub-reflector second focus and the radius of a focal ring of the main reflector is selected under the following condition:
• 1.015≦Fe2r/Fr≦1.6
• wherein the 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
• wherein
• Fe2r is the focal ring radius of the sub-reflector second focus placed away from the axis,
• Fr is the focal ring radius of the main reflector.