Smolcic, V.V.SmolcicPadovani, P.P.PadovaniDelhaize, J.J.DelhaizePRANDONI, ISABELLAISABELLAPRANDONISeymour, N.N.SeymourJarvis, M.M.JarvisAfonso, J.J.AfonsoMAGLIOCCHETTI, MANUELAMANUELAMAGLIOCCHETTIHuynh, M.M.HuynhVaccari, M.M.VaccariKarim, A.A.Karim2020-04-152020-04-15201597819092047061824-8039http://hdl.handle.net/20.500.12386/24049In this Chapter we present the motivation for undertaking both a wide and deep survey with the SKA in the context of studying AGN activity across cosmic time. With an rms down to 1 $\mu$Jy/beam at 1 GHz over 1,000 - 5,000 deg$^2$ in 1 year (wide tier band 1/2) and an rms down to 200 nJy/beam over 10 - 30 deg$^2$ in 2000 hours (deep tier band 1/2), these surveys will directly detect faint radio-loud and radio-quiet AGN (down to a 1 GHz radio luminosity of about $2\times10^{23}$ W/Hz at $z=6$). For the first time, this will enable us to conduct detailed studies of the cosmic evolution of radio AGN activity to the cosmic dawn ($z\gtrsim6$), covering all environmental densities.ELETTRONICOenConference paper10.22323/1.215.0069https://pos.sissa.it/215/069/2015aska.confE..69SFIS/05 - ASTRONOMIA E ASTROFISICA