Shielding material for public buildings against the electromagnetic field radiation of the base station antennas

Wireless communication systems have developed well for the last ten years. Since EM fields are important for human health and electronic systems' safety, shielding materials are becoming of great interest. Different types of electromagnetic isolation materials have been developed. These are commonly based on copper, nickel, ferrite, etc., or their composites. However they are not optimum for public use due to their cost, installation conditions, advantages in daily life. A new material is proposed for electromagnetic shielding for public use. It is not only effective against the electromagnetic fields radiated from base station antennas, but also provides thermal isolation and sound attenuation in buildings. The proposed material is a 2 to 5 cm thick sandwich like panel whose substrate consists of a polyurethane or phenolic material, with both sides covered by smooth or embossed aluminium foil or polyester, with thickness of 28 /spl mu/m to 200 /spl mu/m. The effectiveness of the material has been measured using different indoor-outdoor antennas.