A measurement campaign has been carried out in a reference indoor environment - a medium-size meeting room - using an ultra-wideband channel sounder operating at 3 different frequency bands: 10 GHz, 60 GHz and 300 GHz. Automatic rotational units are used at Tx and Rx side to perform a full horizontal scanning with directional antennas, in order to achieve a doubledirectional channel characterization. Preliminary results show that multipath is mainly affected by few single or double-bounce components, and significant contributions may come from objects other than the walls, e.g. TV monitor and entrance door. Most of the contributions are clearly identifiable at all the considered frequencies, although they appear to be stronger at 60 GHz com...