Abstract

In this paper, three dimensional finite element method is used for the analysis of thin film bulk acoustic wave resonator (TFBAR) at 5GHz. The TFBARisplaced on thin membrane after removal of substrate materialfor the suppression of loading effects and threedifferent geometries (rectangular, polygonal and circular)are implemented and modeled. The size of fabricated TFBAR are from100x100um2 to 200x200 um2 and full-wave modeled results are compared with the measurement.It is found that the modeled and measured results agree within 1% in terms of series and parallel resonant frequencies. Furthermore, the different shapes of TFBAR revealed slightly different bandwidth characteristics, whichis defined on frequency spacing between the series and parallel resonant frequencies.The another goal of this workis to study the variation of the size of resonator on how affects the performance of TFBAR. As the size of resonator incease, the electrical impedance of TFBAR decrease at theresonant frequencies and out of resonant frequencies.Thesephenomenacontributeto improve the effects of theattenuations of TFBAR filter in stop-band to some degree.