IEVref: 121-12-18 ID: Language: en Status: Standard Term: effective complex relative permittivity Synonym1: Synonym2: Synonym3: Symbol: εre Definition: under sinusoidal conditions in a medium where the phasors D, E and J representing respectively the electric flux density, the electric field strength and the electric current density are linearly related, complex quantity εre defined by the relation ${\epsilon }_{0}\text{\hspace{0.17em}}\text{\hspace{0.17em}}{\underset{_}{\epsilon }}_{\text{re}}\text{\hspace{0.17em}}\underset{_}{E}=\underset{_}{D}+\frac{\underset{_}{J}}{\text{j}\omega }=\underset{_}{D}-\text{j}\frac{\gamma \text{\hspace{0.17em}}\underset{_}{E}}{\omega }$ where γ is the conductivity of the medium, ω the angular frequency and ε0 the electric constant NOTE 1 – The effective complex relative permittivity is generally frequency dependent. For an isotropic medium the effective complex relative permittivity is a scalar; for an anisotropic medium it is a tensor. NOTE 2 – The effective complex relative permittivity and the complex relative permittivity εr are linked by the relation $\text{\hspace{0.17em}}{\underset{_}{\epsilon }}_{\text{re}}\text{\hspace{0.17em}}={\underset{_}{\epsilon }}_{\text{r}}-\frac{\text{j}\gamma \text{\hspace{0.17em}}}{{\epsilon }_{0}\omega }$ In a conductive medium, including good conductors and imperfect dielectrics, the useful and measurable quantity is the effective complex relative permittivity. NOTE 3 – The negative of the imaginary part of the effective complex relative permittivity represents both dielectric losses and losses due to the conductivity, the part due to conductivity being represented by γ/ε0ω. Publication date: 1998-08 Source: Replaces: Internal notes: 2017-06-02: Cleanup - Remove Attached Image 121-12-181.gif 2017-06-02: Cleanup - Remove Attached Image 121-12-182.gif CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: