A shaped shielding in office block environment

The increase of wireless systems in big cities has brought its consequences. In Buenos Aires, for instance, many FM broadcasting transmitting antennas are installed on top of high buildings. Some of these are only office buildings, but some others have also apartments. In general, the main FM broadcast stations have very high power transmitters, with powers beyond 20kW and arrays of antennas with 6 or more cross-field elements. This situation becomes more complex when the top of the building houses many radiation systems and when the electromagnetic field levels existing within the offices or the apartments on the top floor surpass the limits established in the Non-Ionizing Radiation national protection guidelines or cause electromagnetic interference problems. When there is no possibility for decreasing the transmitters´ power, a proper shielding can be the solution to attenuate these field levels below the guidelines limits. This paper compares the performance of two different shieldings designed to attenuate field levels in the top floor of “Tower MOP”, in Buenos Aires, by examining their simulated and measured results.