Wide band-pass FSS with reduced periodicity for energy efficient windows at higher frequencies

A simulation model and an experimental characterization of energy saving glazing transparent to mobile communication frequency up to 40 GHz is presented. A previous study showed that laser structured energy efficient windows with a frequency selective surface greatly reduces the microwave attenuation for frequencies below 5 GHz, while preserving the thermal insulation properties of the window. In this study, the focus is laid upon higher frequency range (26-40 GHz), considering the rapid evolution of the carrier frequencies. Several energy efficient windows were built and laser scribed with a cell periodicity down to 0.5 mm. A computational model based on electric equivalent circuit behavior and transfer matrix representation is shown, and compared to a real set of measurements taken from the manufactured glazing. The simulated data strongly fit the measurements taken for five different windows, and, additionally, it allows to infer parameters of a real double-glazing that may be difficult to measure directly. To the best of our knowledge, this is the first time energy efficient windows are produced with these characteristics, measured and simulated at high frequency range.