Main Research Interests
Artificial Materials with Higher Symmetries
Higher-symmetric structures are periodic structures whose unit cell is symmetric with respect to a geometrical operator, such as the glide or the twist operator.
Artificial materials based on these symmetries can achieve a very low frequency and spatial dispersion, high confinement when used in a band-gap (10.1109/JMW.2020.3033847).
I work on numerical and analytical modeling of this class of structures (here and here) and the design of lenses and circuits exploiting their properties (e.g. here and here).
I am the Main Chair of SyMat, a European COST Action working on these and related topics: symat-cost.eu
Numerical Methods for Waves in Periodic and Layered Media
I work on integral-equation formulations for wave scattering and propagation in periodic/layered environments, for the design of frequency-selective surfaces, leaky-wave antennas, EBG, metamaterials.
I work on Green's function computation (here and here) and interpolation (here), on the nonperiodic excitation of periodic structures (here), and on semi-analytic methods for the analysis of periodic structures (here). Periodic structures can be used to engineer the frequency dispersion of metamaterials and either suppress the dispersion (see previous section) or obtain giant resonances (here).
Among my works involving analytical methods, together with Prof. David Jackson of University of Houston and Prof. A. Galli of Sapienza University, we have derived rigorous closed-form expressions for the number of surface waves supported by a general multilayered structure.
Substrate-Integrated Waveguides: Modeling and Design
Substrate-integrated waveguides (SIW) are integrated waveguides realized by drilling vertical via holes in a dielectric substrate to simulate vertical metallic walls. Slots etched on the top plate can make the structure radiate. Together Prof. M. Casaletti (GeePs, Sorbonne Université) we have developed a hybrid code coupling a mode-matching to model the cylindrical vias and a MoM to discretize the slots (here, here and here). The code is capable to analyze and optimize complex structures with hundreds of slots and thousands of vias.
Applications spans from slot waveguides, near-field focusing aperture, X-wave pulse launchers, radial-line slot arrays for satellite communications, periodic SIW exhibiting giant resonances for high quality-factor resonators.
Millimeter Waves for e-Health
Millimeter waves are an attractive frequency band for e-health in Body area networks (BAN) applications, due to the availability of the free 57–64 GHz range, the small-size of devices, and low interference among adjacent BAN.
Another e-health application developed together with Prof. J. Sarrazin (GeePs, Sorbonne Université) is the millimeter-wave radar doppler for the detection of vital signs (hearthbeat, respiration).
Near-field shaping is interesting for a great number of applications, such as medical imaging, diagnostics, wireless power transfer, near field communications. Together with Dr. M. Ettorre at IETR and Prof. A. Galli's group at Sapienza University, we have worked on the near-field focusing by means of low-profile structures at millimeter waves, with both monochromatic beams and wideband pulses (here and here).
