Micromechanically Tunable Dielectric Rod Resonator

A resonant frequency control method for dielectric rod resonators is discussed. A dielectric rod of cylindrical shape is placed inside a metal cavity. The bottom face of the dielectric rod is fixed at the metal base plate. Resonant frequency tuning is achieved by lifting the top metal plate above the dielectric rod upper face. The paper presents simulations using the mode matching technique and experimental study of this tunable resonator. Resonant frequency of the basic mode can be tuned by more than an octave with displacements of only tens of micrometres, which is in range of piezoactuators, MEMS, etc. A distinct feature of the proposed tuning technique is that the quality factor of the system does not degrade throughout the tuning range.