Modern architecture of tertiary buildings includes employing state of the art materials to optimise energy efficiency. The usage of thermo-isolated windows brought along the reduction of signal transmissibility and in the end the difficulty of users inside to have enough reception for phone calls and other smartphone usages. Costly solutions of signal repetitions inside the buildings were put in place.
Based on their research on frequency selective surface (FSS), the Grenoble laboratory on radiofrequency IMEP LAHC has developed a solution to increase the transmissibility of signals through thermo-isolated windows. Its consists in printing conductive cell units onto removable plastic films (intelligent plastics). This solutions is not sensitive to the angle of incidence nor to the polarisation. The films are destined to be simply put on the window; they will be stuck up by the adhesive power of the plastic film. They allow to increase the signal by about 15dB at the desired frequencies.
Demonstrating films for specific frequencies, combinations of wide band are available for testing. Different printing technologies and inks used show different grades of transparency. The augmentation of 15dB has been validated and current works optimise the cell unit to obtain 15dB. Further printing trials are planned to further optimise transparency.
WinApps proposes a solution increasing the transmissibility of signals through thermo isolated glass.
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