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 smart phone usages. Costly solutions of signal repetitions inside de buildings were put in place.
Based on their research on frequency selective surface (FSS), the Grenoble laboratory on radiofrequency IMEP LAHT has developed a solution to increase the transmissibility of signals. through thermo-isolated windows. Its consists printing conductive cell units onto removable plastic films (intelligent plastics). This solutions is not sensitive to the angle of incidence nor to polarisation. The films are destined to be simply put on the window and stick due to the adhesive power of the plastic film. They allow to increase at least about 10dB at the desired frequencies.
Demonstrating films for specific frequencies, combinations or wide band are available for testing. Different printing technologies and inks used show different grades of transparency. The augmentation of 10dB 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