Analysis and Design of High-Efficiency Metasurface Antennas for SATCOM Applications

This thesis presents the design, numerical validation, and implementation of innovative metas- urface (MTS)-based antennas for advanced communication applications. The research explores novel techniques for achieving dual-polarization, multi-beam capabilities, and high-efficiency low-profile antenna structures, particularly in the Ka-band, to address the growing demands of satellite communications and telecommunication networks. The first part of this work invest- igates a dual circularly polarized metasurface antenna that utilizes inward and outward surface wave duplexing. This design enables shared aperture utilization, where an integrated triaxial feeding mechanism excites inward and outward traveling surface waves independently. The interaction of these waves with an unwinding spiral metasurface impedance pattern gener- ates left-handed and right-handed circularly polarized beams, ensuring efficient radiation while maintaining a compact structure. The second part extends this concept to a multi-beam dual-polarized metasurface antenna, which employs an advanced modulation technique to enable simultaneous beam generation. Four different approaches are analyzed: the first one addresses broadside radiated beams, the second one squinted radiated beams, the third one seg- ments the aperture into independent beam-generating sectors and the last one exploits multiple modulations over a shared aperture. A novel triaxial feeding system is introduced, facilitating efficient dual-polarized beam formation with high angular precision. The final contribution fo- cuses on a high-efficiency low-profile full-metal Continuous Transverse Stub (CTS) antenna array for Ka-band satellite communications. The proposed antenna comprises two stacked circular parallel plate waveguides (PPWs) for beamforming and radiation. A bottom planar Meta-lens based beamformer and a top CTS radiating structure enable unconventional mechanical beam scanning while ensuring broad impedance bandwidth and radiation efficiency. The resulting design demonstrates the potential for high-gain, wideband performance with low profile, making it a promising solution for next-generation satellite networks. By combining metasurface-based approaches with innovative feeding architectures, this thesis demonstrates novel antenna solutions that achieve high efficiency, compactness, and enhanced radiation con- trol. These contributions pave the way for the development of advanced, lightweight, and power-efficient antennas for space and terrestrial communication systems.