Loss balance in tunable ferroelectric FBARs

Distinguishing between different loss mechanisms and their distribution between different parts of the Film Bulk Acoustic Wave Resonators (FBAR) is an issue. In this work a scaling rule (based on the analysis of the loss mechanisms) is proposed for initial specification of the losses in different structural components of the tunable FBARs. Simple ADS based calibration procedure is then applied allowing for correction of these losses and identifying the lossiest component. It is shown, in the provided example that the losses due to scattering at the roughness of the top Al electrode is dominating. Polishing of Al is proposed as a possible way of scattering losses reduction.