Source adapted from Ref. 2 The loss mechanism is characterised by the relative loss factor term ε˝, which is part of the
complex relative permittivity, whereas absolute permittivity is given by ε = εοε*. The two
components of the complex relative permittivity shown plotted as a function of the frequency in
Fig. 1, for a dipolar liquid or for a wet dielectric, where the losses at microwave frequencies are
due to re-orientation polarisation. The conductivity effects of ionic species, shown by the light blue
response, dominate at radio frequencies, while the combined loss is shown by the red response.