An ultra-wideband antenna array architecture includes a first array of radiating elements, a second array of radiating elements, and a third array of radiating elements, with their respective element widths proportionately ascending in size. In one configuration, the first array radiating element width is half a wavelength at the highest frequency of operation, the second array element width is twice the first width, and the third array element width is twice the second width. The first, second, and third arrays are positioned in a wavelength-scaled lattice wherein the wavelength scaling is based on design operative frequencies and whereby adjacent actively-radiating elements for an operative frequency are aligned so as to produce constructive interference when powered up. Feed means such as a diplexer with a selected-band frequency control then provides power to each array.