Engineered graphene for optically transparent microwave devices

Most of microwave devices are not optically transparent in the visible range. Optically transparent microwave devices, such as absorbers, filters and antennas, would be desirable since they could be fully exploited for shielding systems, military applications or integrated in window glasses and along with photovoltaics. These devices could also play a key role in micro- and nano-satellite applications where the maximization of the surface area for the solar power collection remains a critical issue. In this paper, we will review configurations of graphene-based microwave devices that attempt to be optically transparent. In this framework, we will also propose our latest results on the realization of microwave absorbers fully transparent in the optical regime. These devices are based on the Salisbury screen configuration, which consists of a lossless spacer (glass) sandwiched between two graphene sheets whose sheet resistances are different and properly engineered.