In a severe multipath environment the antenna receives multiple copies of the same transmitted signal. To solve for all waves is difficult if possible at all. In this paper we use the approach of grouping the spatio-temporalreflections into clusters. We study how the aperture and bandwidth affects the cluster resolution using experimental data. The measurements were obtained by transmitting linear FM (chirp) signals of 150 MHz bandwidth, in the 1800 MHz band. An antenna array of 16 elements was used as a receiver.