Shielding performances of innovative transparent metals against radio frequency EM fields

The paper presents a new transparent metal characterized by a non-periodic structure, overall thickness of about 0.7 /spl mu/m, radiofrequency shielding effectiveness higher than 40 dB up to 6 GHz, optical transmittance up to 70%. The new nanostructured material is designed by considering the constraints of low bonding impedance and high optical transmittance. The effects of different bonding solutions and sample realization procedures are analysed and discussed. The study is developed within a two year research project finalized to the design, realization, and testing of innovative electromagnetic shields for radio frequencies, which are transparent in the visible range. The project is carried out by the electromagnetic compatibility group and the physical optics group of the University of Rome "La Sapienza", in collaboration with the ENEA Research Center.