COMPACT MEMS BASED RECONFIGURABLE BAND-PASS MICROSTRIP FILTER USING DEFECTED GROUND STRUCTURE (DGS)

A new compact MEMS-based reconfigurable bandpass filter is presented. The proposed structure consists of symmetrically coupled DGS resonators, etched in the ground plane, with a microstrip excitation to obtain a bandpass filter response. The reconfigurability is achieved by short circuiting part of the slots etched in the ground plane using RF MEMS switches. The structure is optimized in order to allow soldering the MEMS switches and implementing the bias strips. A reconfigurable bandpass filter is designed, analyzed, and implemented on Duroid dielectric substrate with 2.2 dielectric constant and 0.78 mm thickness. The filter is designed to switch between the two center frequencies 1.62 and 1.85 GHz with approximately 7.5% relative bandwidth. The measured results are in good agreement with the simulations.