"Two main lines have been explored: diffractive optical and photonic band-gap elements. In the first line, work has been focused on the optimization of the power coupled to equally intense output beams: following our previous results on three- and four- beam elements, we have derived an optimum-efficiency multiplier, with an arbitrary number of output beams, and have given its phase transmittance in an analytic form. For the second line the possibility of enhancing the directivity of a planar antenna has been explored, in particular we designed, fabricated, and tested a woodpile PBG and a patch antenna, obtaining more than 10 dB of gain increase. "
Pajewski, L., Ponti, C., Schettini, G. (2012). Analysis and Design of Diffractive-Optical and Photonic Band-Gap Elements: Activities during the COST ACtion MP0702. In Proceedings of Micro- and nano- photonic materials and devices MINAP 2012 (pp.137-140). CNR.