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In this paper it is presented the fabrication of low loss millimeter wave metamaterials based on patterning on polypropylene substrates by conventional contact photolitography. We study numerically and experimentally the transmission and reflection properties of two dimensional arrays of split ring resonators (SRRs), or metasurfaces, and their complementary structure (CSRRs) for co- and cross-polarization excitations up to submillimeter frequencies under normal incidence conditions. The obtained results suggest the possibility of scaling them at terahertz frequencies based on this substrate where other lossy substrates degrade the resonators quality. Left-handed metamaterials derived from these SRRs and CSRRs metasurfaces could be feasible.

We review our recent results on development of passive quasi-optical selective devices based on metallized subwavelength microstructure arrays designed for controlling radiation beams at frequencies from a few tens GHz up to ten THz: filters, polarizers, metasurfaces, ET-metamaterial lenses. The methods of electromagnetic simulation, technological implementation and (sub)THz-characterization of microstructure devices, as well as their applications, are discussed.

In this letter it is presented a Left-Handed Metamaterial design route based upon stacked arrays of screens made of complementary split rings resonators under normal incidence in the microwave regime. Computation of the dispersion diagram highlights the possibility to obtain backward waves provided the longitudinal lattice is small enough. The experimental results are in good agreement with the computed ones. The physics underlying the Left-Handed behavior is found to rely on electroinductive waves, playing the mutual capacitive coupling the major role to explain the phenomenon. Our route to Left-Handed metamaterial introduced in this paper based on stacking CSRRs screens can be scaled to millimeter and terahertz for future applications.

We have experimentally realized at microwaves a dual-band ultraslow regime by constructing a metamaterial based upon the alternative stack of conventional- and complementary-split-ring-resonators-surfaces. The group delay reaches values larger than two orders of magnitude than those obtained when the electromagnetic wave propagates the same thickness in free-space. The ultraslow waves have been initially predicted by a numerical eigenmode analysis and finite-integration frequency domain simulations. Such ultraslow modes can be integrated into free-space technology for spatial delay lines, and traveling wave amplifier as well as sensors due to the enhanced interaction between different beams or radiation and matter.