Double layer interwoven frequency selective surfaces

The application of double layer interwoven Frequency Selective Surfaces to obtain wideband isolation at mobile phone frequency bands while allowing transparency at the emergency TETRA and the Bluetooth bands is proposed. The intention is to modify the EM architecture of buildings over a very wide frequency range, permitting access at these two very separated bands. In particular, we have in mind buildings with restricted mobile phone usage such as public libraries, theatres and secure offices.