Feitor, BrunoCaldeirinha, RafaelFernandes, Telmo, Telmo Rui Carvalhinho Cunha, Telmo R.Ferreira, DavidLeonor, Nuno2025-11-042025-11-042011-11In this paper, microwave and millimetre wave reflection coefficient measurements at 18.7 and 60 GHz are presented for a group of concrete slabs, in which only the thickness of the gravel present inside is varied. An empirical reflection coefficient value is determined using both reflected and LOS power measurements. A concrete slab with no gravel is used as a reference. The measurement results show the dependence of the reflection coefficient with the thickness of the gravel inside the slab. The measurement results allow for the appropriate extraction of dielectric properties of the materials under study.978-1-4577-1014-8http://hdl.handle.net/10400.8/14500In this paper, microwave and millimetre wave reflection coefficient measurements at 18.7 and 60 GHz are presented for a group of concrete slabs, in which only the thickness of the gravel present inside is varied. An empirical reflection coefficient value is determined using both reflected and LOS power measurements. A concrete slab with no gravel is used as a reference. The measurement results show the dependence of the reflection coefficient with the thickness of the gravel inside the slab. The measurement results allow for the appropriate extraction of dielectric properties of the materials under study.engconference paper10.1109/lapc.2011.6114146