• frequency selective surfaces
• high index of refraction media
• low index of refraction media
• negative index of refraction media
• planar metamaterials
• quasi 2-D isotropy
• small antennas
• thin absorbers.

In this work, the synthesis of novel metamaterials by using planar multilayered frequency selective surfaces (FSS) is addressed. In the first part we address the problem of the
realization of high-index of refraction and low-index of refraction media that reveal
extremely stable to angular variations of a TE incident plane wave. Then we shift our
attention to the synthesis of left-handed metamaterials with a quasi-2D isotropic behavior,
still for a TE incident plane wave. In this case, large use is made of a transmission line
model to describe the FSS behavior for normally incident plane waves. In particular, this
model reveals useful for both the synthesis of our solutions and the proof of the effective
medium condition in the working band. A 3-D periodicity cell, whose dimensions are
much smaller than the wavelength in the host medium, will be obtained by resorting to an
equivalence with antennas applications. Once a solution is retrieved for normal incidence,
a dipole-moment approach will be used to physically prove the strong angular stability of
the synthesized structures. To conclude, ideas for a small antenna and for a thin absorber
will be presented: possible implementations for both will be given by elaborating the
same FSS elementary cell employed in the synthesis of the above described
metamaterials.