Abstract: A broadband or multiband antenna for microwaves, optical transmission or mobile telephones in which a reflector plane and at least one radiating element disposed in the vicinity of the reflector plane are provided. An assembly of defective PFB material elements is superposed on the reflector plane and the radiating element. Each defective PFB material element is substantially plane, parallel to the reflector, and presents at least one characteristic of magnetic permeability, of dielectric permittivity, and/or of thickness in the direction perpendicular to the reflector that differs from one defective PFB material element to another. The assembly forms a leaky resonant cavity.

Abstract: The invention concerns a broadband or multiband antenna for microwaves, comprising a reflector plane (R) and at least a radiating element (ER) arranged proximate to the reflector plane (R). A assembly of photonic forbidden band material default elements is superimposed on the reflector plane (R) and the radiating element (ER). Each photonic forbidden band material default element is substantially planar, parallel to the reflector (R) and has at least a characteristic of magnetic permeability of dielectric permittivity and/or thickness in the direction perpendicular to the reflector (R) different from one element of photonic forbidden band material to the next. The assembly forms a leaky resonant cavity. The invention is applicable to mobile telephone systems, or optical path transmissions.