Characterization of ferrite tunability at microwave frequencies: Application to VHF tunable antennas

A microwave characterization method that allows extracting permeability variations of ferrite as a function of applied static magnetic field is presented. This method is based on a coaxial line method for which a calibration technique is proposed to take into account the variations of the bias system. Measured permeability spectra are used to design a tunable antenna in VHF frequency band.