Abstract—In this contribution a novel dielectric radio frequency (RF) applicator cell with an open aperture exceeding the beam waist for terahertz (THz) transmission is presented. Dielectric heating equations are shown that explain the relation of losses and temperature of the material under test. Next to fundamental considerations, we are presenting 3D-EM simulations and measurement results of a manufactured RF applicator cell that shows excellent properties within the frequency range from 10MHz to 1 GHz.