Abstract: The invention is based on a planar concept and involves the configuration of a planar radiating element with the property of generating wide-band electromagnetic radiation fields with circular field polarisation. A wide-band radiating element is developed in which the radiating and excitation network planes are separated and excitation of the radiating element is achieved using a coupling waveguide comprising a group of highly conductive planar elements stacked along the normal to their (large) surfaces above a conductive ground plane; to ensure a large radiation band-width, the highly conductive planar elements are placed well above the conductive ground plane and their highly inductive coupling components (which are connected to the ground plane) are compensated by special coaxial waveguide diaphragms whose ellipticity of the circular polarisation is adjusted solely by circular or square diaphragms within the planar contour, without affecting the radiating edges.