  Conventionally, one can constrain the dark matter (DM) interaction with DM
mass heavier than GeV by searching for DM induced synchrotron emission in the
radio frequency band. However, an MeV DM can also generate detectable radio
emission if electrons and positrons produced by DM annihilation or decay
undergoes inverse Compton scattering (ICS) with the cosmic microwave
background. The upcoming radio telescope Square Kilometre Array (SKA) is
designed to operate with extremely high sensitivity. We investigate the
capability of the SKA to detect DM particles in a board mass range from MeV to
TeV, for both annihilation and decay scenarios. In this paper, we consider the
sensitivities of the future SKA first and second phase (SKA1 and SKA2). As a
comprehensive study, we systematically study the impacts on the DM-induced
signal computation from the magnetic field strengths and particle diffusion
coefficients. We compare the detection potential of four very different
sources: two dwarf spheroidal galaxies (Draco and Segue 1), one radio-poor
cluster (A2199), and one DM-rich ultra-diffuse galaxy (Dragonfly 44). We
project the SKA1 and SKA2 sensitivities with the exposure of 100 hours on the
annihilation cross section and decay time for DM mass from MeV to TeV by
considering two different leptonic final states $e^+ e^-$ and $\mu^+\mu^-$.
