NON-CONTACT DIELECTRIC MEASUREMENTS ON POLYMER FILMS

Abstract

Dielectric characterization of materials in the RF domain is usually carried out on samples with applied electroconductive electrodes. A high-quality contact between a sample and the measuring electrodes provides a stable current flow through the sample and information on the exact value of the electric field in which the sample is located. It also enables a simple measuring instrument to determine the dielectric parameters of the material being tested. However, the presence of contact potentials and the exchange of charge between the test material and the applied electrodes can mask some electrical phenomena in the material or significantly affect how we perceive these phenomena. In order to detect weak electrical processes in the material, for example the photoelectric response of non-polar polymers, contactless dielectric measurements must be carried out. The literature on non-contact dielectric measurements in the RF domain is poor, and because of that, this paper presents the methodology for determining the dielectric parameters of film-shaped materials in conditions of contactless dielectric measurements.