US Patent 7170451 Antenna device having ultra wide bandwidth characteristics

An antenna device having ultra wide bandwidth characteristics includes: a dielectric substrate having first and second surfaces that are opposite to each other in a normal direction; a radiating element formed on the first surface of the dielectric substrate and defining an axis perpendicular to the normal direction; and a grounding element formed on the second surface of the dielectric substrate and cooperating with the radiating element to define first and second imaginary slots in the dielectric substrate. The first and second imaginary slots extend in the normal direction from the first surface to the second surface of the dielectric substrate, and are respectively disposed at two opposite sides of the axis.