Modulated metasurface antennas and arrays for millimeter wave and sub-terahertz applications

International audienceThis summary presents the application of modulated metasurfaces in millimeter wave and sub-terahertz antenna systems. We succinctly show that by adopting metasurfaces as array element, one may mitigate some of the challenges found in large phased arrays with a limited field of view and concurrently enhance the gain bandwidth of modulated metasurfaces antennas with a single port. © 2023, META Conference. All rights reserved

Modulated metasurface antennas and arrays for millimeter wave and sub-terahertz applications

International audienceThis summary presents the application of modulated metasurfaces in millimeter wave and sub-terahertz antenna systems. We succinctly show that by adopting metasurfaces as array element, one may mitigate some of the challenges found in large phased arrays with a limited field of view and concurrently enhance the gain bandwidth of modulated metasurfaces antennas with a single port. © 2023, META Conference. All rights reserved

Higher-Symmetries for Broadband Reflecting Luneburg Lenses at Ka-band

International audienceThis paper reports the application of higher symmetries to the design of a Reflecting Luneburg Lens (RLL) with broadband response. RLLs consist of two circular parallel plate waveguides (PPWs) vertically stacked. The bottom PPW is filled with an azimuthally symmetric graded index (GRIN) medium. Owing to this GRIN medium, the wave launched by a primary feed in the bottom PPW is collimated in the top one, so that a plane wave with a different propagation direction is generated for any azimuthal position of the source. In this work, the GRIN medium in the bottom PPW is implemented by higher symmetry unit-cells consisting of metallic inclusions. This type of unit-cell achieves the required effective refractive index profile with reduced frequency dispersion, thus increasing the operational bandwidth of the lens. The proposed architecture constitutes a low-profile beam-forming solution that also provides complete azimuthal scanning in a wide frequency range. Moreover, it remains completely metallic, thus benefitting from structural robustness and reduced losses

Broadband reflecting Luneburg lens beam-former at Ka-band

International audienceThis papes describes the application of higher symmetries to enable broadband operation of Reflecting Luneburg lenses (RLL) at Ka-band. RLLs are a new type of beam-former, consisting of two vertically stacked parallel plate waveguides (PPWs) of circular shape, of which the bottom one is filled with a graded index (GRIN) medium with azimuthal symmetry. The rays launched by a source in the bottom PPW follow curvilinear paths such that they emerge collimated in the top PPW after encountering a reflecting boundary. Owing to the lens' symmetry, one can generate plane waves with arbitrary directions by simply changing the azimuthal position of the source in the bottom layer. In this paper, the GRIN medium is implemented by loading the bottom PPW with higher symmetric unit-cells consisting of metallic posts. This solution offers a double benefit: it allows one to synthesize the somehow high refractive indexes in the RLL profile and it also mitigates frequency dispersion, thus increasing the lens operational bandwidth. The proposed architecture constitutes a metal-only, low-profile beam-former that can provide full azimuthal scanning in the whole Ka-band

Reflecting Luneburg Lens : une nouvelle lentille à gradient d’Indice

International audienceNous introduisons la lentille de Luneburg réflective (Reflecting Luneburg lens, RLL), un formateur de faisceau innovant conçu pour surmonter les contraintes plus significatives des lentilles de Luneburg planaires conventionnelles et des autres formateurs, comme le coupleur pillbox. Les RLL offrent de nombreux avantages : balayage total en azimut, possibilité de générer des faisceaux pincés et faible profil. Elles sont également applicables pour une vaste variété de dispositifs fonctionnant en micro-onde, en gamme THz et en optique

Higher-Symmetries for Broadband Reflecting Luneburg Lenses at Ka-band

International audienceThis paper reports the application of higher symmetries to the design of a Reflecting Luneburg Lens (RLL) with broadband response. RLLs consist of two circular parallel plate waveguides (PPWs) vertically stacked. The bottom PPW is filled with an azimuthally symmetric graded index (GRIN) medium. Owing to this GRIN medium, the wave launched by a primary feed in the bottom PPW is collimated in the top one, so that a plane wave with a different propagation direction is generated for any azimuthal position of the source. In this work, the GRIN medium in the bottom PPW is implemented by higher symmetry unit-cells consisting of metallic inclusions. This type of unit-cell achieves the required effective refractive index profile with reduced frequency dispersion, thus increasing the operational bandwidth of the lens. The proposed architecture constitutes a low-profile beam-forming solution that also provides complete azimuthal scanning in a wide frequency range. Moreover, it remains completely metallic, thus benefitting from structural robustness and reduced losses

Metal-only Reflecting Luneburg Lens Design for Sub-THz Applications

International audienceThis paper presents a metasurface (MTS) beamformer based on Reflecting Luneburg Lenses (RLLs) operating in the sub-THz range. RLLs consist of two circular parallel plate waveguides (PPWs) vertically stacked. The bottom wall of the lower PPW is loaded with a MTS with an axially symmetric modulation. The wave launched by a primary feed in the bottom PPW is collimated in the top one, so that a plane wave is identically generated for any azimuthal position of the source. The proposed solution uses a bed of nails, wellsuited to fabrication by Si micromachining, to implement the RLL refractive index profile. Simulation results yield a 30%-3dB directivity bandwidth around the center frequency (280 GHz). This device can be used as a beam-former for multi-beam antennas for Earth observation or for front-and back-hauling in beyond 5G wireless

Design of Broadband Reflecting Luneburg Lenses by Higher Symmetries

International audienceThis work reports the application of higher symmetries to the design of a Reflecting Luneburg Lens (RLL) with broadband response. RLLs consist of two stacked parallel plate waveguides (PPW) of circular shape, where the bottom PPW is filled with an azimuthally symmetric graded index (GRIN) medium, so that the fields coupled to the top PPW take the form of a plane wave. In this work, the GRIN medium in the bottom PPW is implemented by unitcells consisting of metallic inclusions with higher symmetry. This type of unit cell achieves the required equivalent refractive index profile with reduced frequency dispersion, thus increasing the operational bandwidth of the lens. The proposed architecture can be used as beam-former for complete azimuthal scanning in a wide frequency range, while benefiting from the robustness and low-losses of metal-only structures. © 2021 IEEE

Higher-Symmetries for Broadband Reflecting Luneburg Lenses at Ka-band

International audienceThis paper reports the application of higher symmetries to the design of a Reflecting Luneburg Lens (RLL) with broadband response. RLLs consist of two circular parallel plate waveguides (PPWs) vertically stacked. The bottom PPW is filled with an azimuthally symmetric graded index (GRIN) medium. Owing to this GRIN medium, the wave launched by a primary feed in the bottom PPW is collimated in the top one, so that a plane wave with a different propagation direction is generated for any azimuthal position of the source. In this work, the GRIN medium in the bottom PPW is implemented by higher symmetry unit-cells consisting of metallic inclusions. This type of unit-cell achieves the required effective refractive index profile with reduced frequency dispersion, thus increasing the operational bandwidth of the lens. The proposed architecture constitutes a low-profile beam-forming solution that also provides complete azimuthal scanning in a wide frequency range. Moreover, it remains completely metallic, thus benefitting from structural robustness and reduced losses

Higher-Symmetries for Broadband Reflecting Luneburg Lenses at Ka-band

International audienceThis paper reports the application of higher symmetries to the design of a Reflecting Luneburg Lens (RLL) with broadband response. RLLs consist of two circular parallel plate waveguides (PPWs) vertically stacked. The bottom PPW is filled with an azimuthally symmetric graded index (GRIN) medium. Owing to this GRIN medium, the wave launched by a primary feed in the bottom PPW is collimated in the top one, so that a plane wave with a different propagation direction is generated for any azimuthal position of the source. In this work, the GRIN medium in the bottom PPW is implemented by higher symmetry unit-cells consisting of metallic inclusions. This type of unit-cell achieves the required effective refractive index profile with reduced frequency dispersion, thus increasing the operational bandwidth of the lens. The proposed architecture constitutes a low-profile beam-forming solution that also provides complete azimuthal scanning in a wide frequency range. Moreover, it remains completely metallic, thus benefitting from structural robustness and reduced losses