As a result of the enormous increase in mobile phone usage throughout the world, mobile phone base stations
are located in almost everywhere nowadays. Many scientific studies have investigated possible health symptoms of
mobile systems radiation. The globally recognised organisations have started to release maximum radio-frequency
(RF) exposure levels that are regarded as safe. An efficient approach to decrease the RF exposure levels inside the
buildings is to transform building walls to a frequency selective surface which filters out global system for mobile
communication signals but allows the others, such as radio and television signals. This study proposes a new
frequency selective surface element geometry which leads to a minimum 20 dB attenuation in 900, 1800 and 2100 MHz
mobile communication bands according to Swiss electromagnetic radiation prevention limit values (NISV, 23
December 1990). High-frequency structure simulator software is used for simulation and design purposes. Due to a
given good insight into the resonance characteristics of the FSS structures, it is benefited from the equivalent circuit
model in the optimisation process. Achieved results show that the proposed FSS element geometry has a stable
frequency response with minimum 20 dB of attenuation levels for transverse-electric (TE) and transverse-magnetic (TM)
polarisations when the angle of incident wave is varied from 0° to 60°.