Authors: M. Naseer, M. Parlak, T. Bechteler, Y. Gurbuz
Affilation: Sabanci University, Turkey
Pages: 388 - 391
Keywords: RF MEMS, filters, coupling spring design, micromechanical resonators
Micromechanical resonators based filters are considered as potential replacements of prevalent tank circuits due to their high selectivity and on chip integration compatibility. Micromachined bandpass filters have been operated both in HF and IF regions with percent bandwidths in the order of 0.2% and 0.09% respectively and insertion losses as small as 1dB. For these high Q designs both the coupling spring as well as insertion loss should be taken into consideration. Design of the coupling spring is studied for mechanically coupled micromechanical filters. Tuning coupling spring, either maximally flat response or maximum bandwidth can be obtained. Tuning criteria is presented theoretically and tested with simulations. Insertion loss is also studied and minimization techniques supported by theory and simulated by the HPADS software are applied using properly designed input/output matching networks. This study assumes identical resonating structures with same resonance frequencies which simplifies the fabrication process.