Ferrite-ferroelectric layered structures for electrically and magnetically tunable microwave resonators

It is demonstrated experimentally that a layered structure consisting of ferrite and ferroelectric thin films can be used as an electrically and magnetically tunable microwave resonator. The dual tunability is realized through the application of a bias electric field to the ferroelectric layer (thus changing its dielectric constant), and a bias magnetic field to the ferrite layer. The resonator having central frequency f(0)congruent to 5 GHz and bandwidth Delta f=3.5 MHz demonstrated a broadband (similar to 300 Delta f) tunability through the variation of the bias magnetic field, and a narrow-band (similar to 2 Delta f) tunability through the variation of the bias electric field. (c) 2006 American Institute of Physics.