A polarizing reflector for broadband antennas comprises a flat dielectric substrate (4), a patch array layer (6) formed by a bi-dimensionally periodic lattice (16) of thin metallic patches (18) along first and second perpendicular directions x, y, and a ground layer (8).
All the patches (18) have a same shape elongated along the second direction y and form electric dipoles when electrically excited along the second direction y,
For each row (24) the patches (18) of the said row (24) are interconnected by an elongated metallic strip (32) oriented along the first direction x and having a width c.
The geometry of the patch array (6), the thickness h and the dielectric permittivity ε r of the substrate (4), and the width c of the elongated metallic strips (32) are tuned so that
the patch array (6) including the elongated metallic strips (32) induces a fundamental aperture mode and a complementary fundamental dipolar mode along two orthogonal TE and TM polarizations within a single operating frequency band or two separate operating frequency bands, and
the differential phase between the two fundamental modes over the single or the first and second frequency bands being equal to ±90° or to an odd integer multiple of ±90°.
The polarizing reflector can comprise also a curved substrate and a patch array layer formed by a bi-dimensionally lattice of metallic patches along first curvilinear rows and second curvilinear columns.