CIRCULARLY POLARISED RADIATING ELEMENT MAKING USE OF A RESONANCE IN A FABRY-PEROT CAVITY

Circularly polarized radiating element comprising at least one excitation aperture (OE) for a wave that is linearly polarized with what is referred to as an excitation first polarization (Ex), a frequency selective surface (S2) and a metasurface (S1) comprising a two-dimensional and periodic array of metasurface cells (MS), the excitation aperture (OE) opening onto the metasurface (S1), the metasurface cells (MS) all being oriented identically with respect to the excitation polarization (Ex) and configured to: - reflect an incident wave (Eix) having the excitation polarization (Ex) in order to form a reflected wave (Er1x) polarized with the excitation polarization (Ex), and - depolarize and reflect the incident wave (Eix) in order to form a reflected wave (Er1y) polarized with the orthogonal polarization (Ey), having a phase difference substantially equal to 900 with respect to the reflected wave (Er1x) polarized with the excitation polarization (Ex), and having an amplitude substantially equal to the amplitude of a wave (E'tx) radiated by the frequency selective surface (S2), generated from the reflected wave (Er1x) polarized with the excitation polarization (Ex).