Interdigitalcapacitor loadedelectric-LCresonator for dielectric characterization

摘要

A high sensitivity microstrip line-based sensor loaded with the electric-LC (ELC) resonator is proposed in this work for the accurate characterization of dielectric materials. The high sensitivity in the present situation is achieved due to usage of novel interdigital capacitor in the ELC resonator topology, which actually provides enhanced electric field for dielectric testing. The proposed sensor is designed in the S band regime, and various standard dielectric samples are tested to validate the proposed design. For retrieving the dielectric constants of these samples, an empirical relationship is proposed relating the dielectric properties with the resonant frequency of the sensor. The proposed empirical model is further improved by introducing two error terms to take into consideration the effect of fabrication tolerance of the sensor and surface roughness of the test specimen. The normalized sensitivity of the proposed sensor using standard procedure is estimated to be 5.14%, which is reasonably higher than that of other sensors reported in literature.