Electric properties of sodium potassium niobate ceramic doped antimony (Na0.5K0.5)(Nb0.93Sb0.07)O-3 with sintering aid MnO2 (0.5 mol% MnO2) (KNNSbx + 0.5Mn) were investigated in a broad frequency (from 1 Hz to 54 GHz) and temperature (from 110K to 800 K) ranges. The mean relaxation times calculated from the dielectric permittivity measurements fulfill Arrhenius relationship with dipole activation energy E-A = 3409 K (E-A/k(B)= 0.29 eV). The DC conductivity has been extracted from experimental results and the activation energy was calculated E-A = 11733.78 K (E-A/k(B)= 1.011 eV). (C) 2012 Elsevier B.V. All rights reserved.