Long wavelength polarization in a spherical particle containing mobile charges

A transport-based formulation is developed for determining the electric polarization in a sphere excited by an axial dynamic electric field to address the resulting dipole moment in the long wavelength region. The difficulty arising from using bulk conductivity is seen to be absent from the newly obtained computation results. This can be attributed to the provision to incorporate the boundary condition for the charge carriers at material interface. For particles with a moderate charge concentration, such as the cases of semiconductor or imperfect dielectric, the frequency range where the dipole moment makes the transition to the static limit falls into the RF and microwave bands. As a result, composite materials containing such particles have the potential to be made to exhibit controllable electrical properties that could find applications in antennas and radio frequency devices