Polarizing reflector for multiple beam antennas

The polarizing reflector for broadband antennas and for converting a same linear polarization into a given circular polarization handedness over one frequency band when operating in a single wideband at normal incidence illuminated by a plane wave, or into a first given circular polarization handedness over a first frequency band and into a second handedness over a second frequency band, the first and the second circular polarization handedness being substantially equal or orthogonal when operating in dual-band at normal incidence illuminate by a plane wave,

• the polarizing reflector comprising
• a flat dielectric substrate delimited between a first surface and a second surface, having a thickness h and a dielectric permittivity εr, and
• a patch array layer formed by a first bi-dimensionally periodic lattice of thin metallic patches and a second bi-dimensionally periodic lattice of thin metallic patches, both laid on the first surface of the substrate, and
• each of the first and second periodic lattices having a first set of patch rows oriented along a same first direction x with a same periodicity dx and a second set of patch columns oriented along a same second direction y with a same second periodicity dy, and
• a ground layer formed by a plain metallic layer on the second surface, located below the patch array layer;
• the substrate separating the patch array layer and the ground layer,
• all the patches having a same shape elongated along the second direction y and forming electric dipoles when excited along the second direction y,
• the polarizing reflector being wherein
• for each row of the first lattice and the second lattice, the patches of the said row have and are all crossed by an elongated metallic strip oriented along the first direction x and having a width c, the elongated metallic strip forming one and a same integral piece, and
• the first and the second lattices of the patches including the elongated metallic strips are geometrically interleaved while being spatially separate, and
• the geometry of the patch array, the thickness h and the dielectric permittivity εr of the substrate, and the geometry of the elongated metallic strips are tuned so that
• the patch array induces a fundamental aperture mode and a complementary fundamental dipolar mode along two orthogonal TE and TM polarizations within the single frequency band when operating in a single wide band or induces a fundamental aperture mode and a first complementary fundamental dipole mode along two orthogonal TE and TM polarizations within the first frequency and the fundamental aperture mode and a second complementary higher order dipole mode along two orthogonal TE and TM polarizations within the second frequency band when operating in dual wide band,
• the differential reflection phase between the two fundamental aperture and dipole modes over the single band, or the differential reflection phase between the two fundamental aperture and dipole modes over the first frequency and the reflection differential phase between the fundamental aperture and a higher dipole mode over the second frequency band being equal to ±90° or to an odd integer multiple of ±90°.

A flat polarizing reflector for a broadband antenna locally illuminated at normal or oblique incidence by an electromagnetic source having a predetermined radiation pattern to the flat polarizing reflector and for converting locally a linear polarization into a given local circular polarization handedness over one frequency band when operating in a single wideband at a local normal or oblique incidence illuminated by a local plane wave originated from a predetermined source radiation pattern, or into a first local circular polarization handedness over a first frequency band and into a second local polarization handedness over a second frequency, the first and the second local circular polarization handedness being substantially equal or orthogonal when operating in dual-band at normal or oblique incidence illuminated by a local plane wave

• the polarizing reflector comprising
• a flat profile dielectric substrate, delimited between a first flat surface with a first flat profile and a second flat surface with a second flat profile, and having a thickness h and a dielectric permittivity εr,
• a patch array layer formed by a bi-dimensionally flat lattice of thin metallic patches on the first surface of the substrate, the flat lattice having a first set of linear patch rows and a second set of linear patch columns,
• a ground layer formed by a plain metallic layer on the second surface, located below the patch array layer;
• the substrate separating the patch array layer and the ground layer, and
• all the patches having a same elongated shape and forming electric dipoles when excited along their own direction of elongation;
• the polarizing reflector being wherein
• for each patch row, the patches of the said patch row are crossed by an elongated metallic strip having a reference width c, or the patches of the said patch row are lined by two elongated metallic strips having a reference width c, and
• the geometry of the patch array, the thickness h and the dielectric permittivity of the substrate, and the geometry of the elongated metallic strips being tuned so that each phasing cell, made of an elongated electric dipole and a portion of the elongated metallic strip crossing the said elongated electric dipole or made of an elongated electric dipole and a portion of the two elongated metallic strip lining the said elongated electric dipole, laid on the grounded flat substrate having a permittivity εr and a thickness h, induces locally a fundamental aperture mode and a complementary fundamental dipolar mode along two local orthogonal TE and TM polarizations within the single frequency band when operating in a single wide band or within the first frequency band and the second frequency band when operating in dual wide band, 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°.

A curved polarizing reflector for a broadband antenna locally illuminated at normal or oblique incidence by an electromagnetic source having a predetermined radiation pattern to the curved polarizing reflector and for converting locally a linear polarization into a given local circular polarization handedness over one frequency band when operating in a single wideband at a local normal or oblique incidence illuminated by a local plane wave originated from a predetermined source radiation pattern, or into a first local circular polarization handedness over a first frequency band and into a second local polarization handedness over a second frequency band, the first and the second local circular polarization handedness being substantially equal or orthogonal when operating in dual-band at normal or oblique incidence illuminated by a local plane wave,

• the polarizing reflector comprising
• a curved profile dielectric substrate, delimited between a first curved surface with a first curved profile and a second curved surface with a second curved profile, and having a thickness h and a dielectric permittivity εr,
• a curved patch array layer formed by a bi-dimensionally curved lattice of thin metallic patches on the first surface of the substrate, the curved lattice having a first set of curvilinear patch rows and a second set of curvilinear patch columns,
• a ground layer formed by a plain metallic layer on the second surface, located below the patch array layer;
• the substrate separating the patch array layer and the ground layer, and
• all the patches having a same substantially elongated shape and forming electric dipoles when excited along their own direction of elongation;
• the polarizing reflector being wherein
• for each curvilinear patch row, the patches of the said curvilinear patch row are crossed by an elongated metallic strip having a reference width c, or the patches of the said curvilinear patch row are lined by two elongated metallic strips having a reference width c, and
• the geometry of the patch array, the thickness h and the dielectric permittivity of the substrate, and the geometry of the elongated metallic strips being tuned so that each phasing cell, made of an elongated electric dipole and a portion of the elongated metallic strip crossing the said elongated electric dipole or made of an elongated electric dipole and a portion of the two elongated metallic strips lining the said elongated electric dipole, laid on the grounded curved substrate having a permittivity εr and a thickness h, induces locally a fundamental aperture mode and a complementary fundamental dipolar mode along two local orthogonal TE and TM polarizations within the single frequency band when operating in a single wide band or within the first frequency band and the second frequency band when operating in dual wide band, and
• the differential phase between the two fundamental modes over the single or the first and second frequency bands i equal to ±90° or to an odd integer multiple of ±90.