RF Acoustic Wave Resonators, Getting Started

RF Surface Acoustic Wave (SAW) resonators are paid much attention also for their use in scientific research such as qubit and spin control in addition to consumer applications. Only one metal layer is necessary for the interdigital electrodes, and high-quality piezoelectric wafers are commercially available with low price. Thus, test devices seem to be easily producible with the help of 2D FEM analysis. However, measured results are commonly much worse than the simulation. This is also true for RF Bulk Acoustic Wave (BAW) resonators even if complexity in fabrication steps is considered. This talk overviews operation of RF acoustic wave resonators. Simple FEM analysis is efficient for initial design and estimation of ideal resonator performances. However, many factors degrade real device performances, and excellent ones are achievable only when everything is good. In other words, many pitfalls are waiting for novices. Representative ones and their countermeasures (if they exist) are introduced, and their impact on device performance is explained with the help of LCR modeling.