Electromagnetic Wave Manipulation Through Metasurfaces: Models and Applications in RF and Microwave Regimes

This thesis investigates the modeling and design of electromagnetic metasurfaces operating from the low radiofrequency (RF) regime to microwave frequencies. Metasurfaces enable tailored manipulation of electromagnetic fields through compact, subwavelength structures, with applications in biomedical technologies, wireless power transfer (WPT), automotive communications, and analog computing. Two complementary approaches are developed. In the low-RF regime, metasurfaces composed of magnetically coupled loop resonators are described using a circuit-based formalism, enabling field focusing, shielding, homogenization, and the implementation of multi-frequency WPT systems. The propagation of magneto-inductive waves is analyzed, and the possibility of performing analog mathematical operations, such as linear combinations and matrix–vector multiplications, is demonstrated through simulations and experiments. At microwave frequencies, metasurfaces are studied using transmission-line models and full-wave simulations with periodic boundary conditions. Applications include automotive antenna enhancement and biomedical matching layers for improved power transfer into tissue. Throughout the thesis, analytical modeling is consistently validated through simulations and measurements, providing a unified and experimentally grounded framework for metasurface design across different frequency regimes.