MEMS tuneable dielectric resonator structures for microwave and millimetre wave applications

In this contribution a novel approach for tuning of dielectric resonators by microelectromechanical switches (MEMS) is presented. This approach is based on intermodal coupling between the TE_01δ mode of a cylindrical dielectric resonator and a planar resonator composed of a patterned metal film. The resonance frequency of the planar resonator can be changed either MEMS leading to a change of the intermodal coupling between the planar resonator mode and the TE_01δ mode. As a consequence, the resonance frequency of the TE_01δ mode changes. As planar resonator structures, we have employed quarter wave resonators each composed of a radially arranged slotline. Upon switching a MEMS located at the open end of the slotline resonator from the capacitive to the resistive state, the fundamental quarter wave resonance is transferred into a halfwave resonance. Due to intermodal coupling, the resonance frequency of the TE_01δ mode changes. Tuning range and quality factors are determined experimentally for a test resonator at 2 GHz. In addition, numerical field simulation illustrating the intermodal coupling is discussed.