Processes of scattering and reflection of wideband signals by non-smooth rough surfaces in the frequency range of 38–52 GHz have been investigated. Dependences of reflection coefficient for various non-smooth surfaces versus distance up to the antenna and the degree of roughness of the sample surface have been obtained experimentally. The influence of behavior and the degree of surface heterogeneity on the value of the reflection coefficient has been estimated using results of the measurements, the influence of spatial orientation of the scattering surface on amplitude of the reflected signal has been revealed.