ULTRABROADBAND ANTENNA
An antenna, intended to transmit and receive radio waves within a given frequency band, comprises at least one radiating element, placed on a flat reflector, comprising a radiating device disposed within a plane parallel to the reflector's plane, at least one conductive line feeding the radiating element, at least one parasitic element disposed above the radiating element, which comprises a two-dimensional base belonging to a plane parallel to the radiating device's plan, associated with a third dimension that gives it a volumic shape.
1 . An antenna, intended to transmit and receive radio waves within a given frequency band, comprising
at least one radiating element placed on a flat reflector comprising a radiating device disposed within a plane P parallel to the plane P′ of the reflector,
at least one conductive line feeding the radiating element, and
at least one conductive parasitic element, disposed above the radiating element, comprising a two-dimensional base belonging to a plane P″ parallel to the plane P of the radiating device, associated with a third dimension that gives it a volumic shape.
2 . An antenna according to claim 1 , wherein the parasitic element is shaped like a truncated pyramid with a square base and a truncated peak.
3 . An antenna according to claim 1 , wherein the parasitic element is composed of four three-dimensional wings forming truncated-pyramid sectors, at an angle of between 30° and 60° inclusive, connected at their tip, the four wings defining a square base and a truncated peak.
4 . An antenna according to claim 1 , wherein the parasitic element is formed of four wings each having roughly the shape of a clipped right triangle, which meet at right angles, the cross-shaped base being defined by the long sides of the right triangles and the peak by the clipped angles.
5 . An antenna according to claim 2 , wherein the side length of the base is about 0.2 λ min , where λ min is the wavelength of the lowest frequency of the frequency band.
6 . An antenna according to claim 2 , wherein the length of the peak's side is about 0.2 λ max , where λ max is the wavelength of the highest frequency of the frequency band.
7 . An antenna according to claim 1 , wherein the parasitic element is shaped like a rounded cone supported by a cylinder.
8 . An antenna according to claim 7 , wherein the diameter of the circular base is about 0.2 λ min , where λ min is the wavelength of the lowest frequency of the frequency band.
9 . An antenna according to claim 2 , wherein the total height of the parasitic element is between 0.05 λ 0 and 0.25 λ 0 where λ 0 is the wavelength of the central operating frequency.
10 . An antenna according to claim 1 , wherein the distance separating the plane P″ of the parasitic element's base from the plane P of the radiating device is about 0.2 λ 0 , where λ 0 is the wavelength at the central frequency of the frequency band.