Wide-Band Characterization of Ferroelectric Thin-Films: Applications to KTN-based Microwave Agile Devices
Résumé
Previous investigations on KTa1-xNbxO3 (KTN) materials evidenced the need to gain insight into the dielectric properties of these films to realize tunable functions with high electrical performances. We, thus, developed a simple and efficient method to determine their dielectric properties at microwave frequencies. It is based on the measurement and analysis of coplanar waveguides (CPWs). The complex permittivity of the film was determined from a modified Spectral Domain Approach. This method was applied, here, to evaluate the permittivity and losses of KTa0.6Nb0.4O3 thin-films deposited on different substrates. The comparison of these results with structural analyses enabled us to observe the influence of the microstructure on the microwave dielectric properties.