A method of manufacturing an array antenna comprising: - a design phase, comprising synthesizing an array layout of said array antenna and choosing or designing radiating elements to be arranged according to said array layout, the design phase comprising the steps of: a. defining a continuous reference aperture; b. subdividing said continuous reference aperture into a plurality of elementary cells with assigned power levels; c. determining, within each elementary cell, a position for the radiating elements, said radiating elements having a field amplitude which is substantially uniform over their whole aperture; d. determining a size and an aperture field amplitude of each radiating element, such that a variation of a cumulative field distribution of the resulting array antenna aperture over each elementary cell is substantially equal to a variation of a cumulative field distribution of said reference aperture over the same elementary cells, subject to size constraints, - a phase of physically making said array antenna, comprising arranging said radiating elements according to said array layout, said array antenna is an aperiodic planar array antenna constituted by concentric annular rings of incommensurable radius and a plurality of radiating elements arranged with each annular ring, the number of radiating elements arranged on each annular ring being proportional to the ratio between the radius of said annular ring and the radial width of said radiating elements, and the radial width of the radiating elements arranged on each annular ring being proportional to the radial width of said annular ring, the radiating elements of the same annular ring having the same assigned power excitations. - a design phase, comprising synthesizing an array layout of said array antenna and choosing or designing radiating elements to be arranged according to said array layout, the design phase comprising the steps of: a. defining a continuous reference aperture; b. subdividing said continuous reference aperture into a plurality of elementary cells with assigned power levels; c. determining, within each elementary cell, a position for the radiating elements, said radiating elements having a field amplitude which is substantially uniform over their whole aperture; d. determining a size and an aperture field amplitude of each radiating element, such that a variation of a cumulative field distribution of the resulting array antenna aperture over each elementary cell is substantially equal to a variation of a cumulative field distribution of said reference aperture over the same elementary cells, subject to size constraints, a. defining a continuous reference aperture; b. subdividing said continuous reference aperture into a plurality of elementary cells with assigned power levels; c. determining, within each elementary cell, a position for the radiating elements, said radiating elements having a field amplitude which is substantially uniform over their whole aperture; d. determining a size and an aperture field amplitude of each radiating element, such that a variation of a cumulative field distribution of the resulting array antenna aperture over each elementary cell is substantially equal to a variation of a cumulative field distribution of said reference aperture over the same elementary cells, subject to size constraints, - a phase of physically making said array antenna, comprising arranging said radiating elements according to said array layout, said array antenna is an aperiodic planar array antenna constituted by concentric annular rings of incommensurable radius and a plurality of radiating elements arranged with each annular ring, the number of radiating elements arranged on each annular ring being proportional to the ratio between the radius of said annular ring and the radial width of said radiating elements, and the radial width of the radiating elements arranged on each annular ring being proportional to the radial width of said annular ring, the radiating elements of the same annular ring having the same assigned power excitations.