High permeability and high permittivity heterostructures for the miniaturization of Radiofrequency components
Résumé
This paper discusses on the miniaturization of radiofrequency (RF) front-end components such as half-wavelength resonators based on new magneto-dielectric heterostructures combining high permeability (µ = 150-250) and high permittivity (ε = 18-150). Size reduction is evaluated by means of 2-cm-long coplanar waveguides realized with silicon technology and having a resonance frequency of about 3 GHz. The experimental results show a physical length reduction of 11.2% due to the dielectric contribution (ε = 18) and 14.8% by cumulating dielectric and magnetic effects (ε = 18 and µ = 150). These results are significant with respect to the moderate thickness of the preliminary material used here (only 150 nm). In a second part, a predictive model is proposed with µ and ε as variables. When adjusting the material properties in a realistic way (µ = 250 and ε = 150), the model predicts size reduction of ~50% for the same thickness. Larger values can be expected with increasing the film thickness.