Interdigitated Planar Microwave Sensor for Characterizing Single/Multilayers Magnetodielectric Material

Simultaneous characterization of permittivity and permeability of magnetodielectric materials using a single resonator-based microwave sensor is challenging due to their similar impacts on the sensor’s response. This work presents an interdigital structure-based planar microwave resonator sensor featuring high-intensity electric (E)-field zones and magnetic (M)-field zones to characterize permittivity and permeability. The proposed sensor’s sensing E-field and M-field zones were implemented using the interdigital fingers configured as a spur line structure and interdigital electrodes, respectively, generating a 5.9-GHz resonance frequency with a high Q-factor (1700). The resonance frequency of the designed sensor exhibited high sensitivities (324 MHz/ $\Delta \varepsilon _{r}$ for permittivity and 825 MHz/ $\Delta \mu _{r}$ for permeability) for characterizing single/multilayers magnetodielectric materials with excellent resolutions (0.324 for permittivity and 0.825 for permeability). The demonstrated high sensitivity and resolution results validate the performance of the interdigital structure-based microwave resonator sensor for simultaneous characterization of multilayer magnetodielectric materials.