The focus of this paper is the evaluation of the mono-static Radar Cross Section (RCS) of a commercial Drone (IRIS) through both simulation and measurements in the 1-4 GHz frequency range. In particular, for the simulations an approximate model of the drone geometry and its material complex permittivity was carried out by means of an electromagnetic CAD. Most importantly, measurements have been performed in an anechoic chamber equipped with a network analyzer and a horn antenna. The obtained results show RCS values between-18 dB and-1 dB in the 1-4 GHz frequency range. This preliminary analysis sets a solid ground for the selection of anti-drone radar carrier frequency when using both conventional and passive radars.