A printed antenna includes a dielectric substrate having a pair of printed
antenna elements to form a dipole antenna. On an antenna plane, an xy
axis system is defined so that an origin is defined at a center of
location of the antenna elements, and an x axis is set in a direction
that the antenna elements are arranged, a y axis is set in the direction
perpendicular to the x axis, and a size of the antenna elements in the
direction of the y axis become gradually larger according to the x axis
changing in an outer direction. Each of the antenna elements has an
impedance matching part at a feeding side of the antenna elements. The
printed antenna can be used in an ultra wide-band frequency, and is small
profile, is light weight and low in cost.