**6.2.3 Radiating structures**

Even for radiating structures only one system has been published. A radiating system, based on a horn antenna, with the perfusion chamber placed in the far-eld region, was used in (Yoon et al., 2006). The biological protocol was the same described in (Hagan et al., 2004), but the exposure frequencies were higher (1-6 GHz). For this higher frequency range, a standard waveguide is too small to accommodate the sample and the cellperfusion apparatus and a radiating system is necessary. However, this solution required a special arrangement to avoid interference with the experimental equipment that was shielded in a conducting box behind the perfusion chamber and a layer of absorber material was used to prevent electric eld reection. The whole system was placed within an anechoic chamber.
