Bulk acoustic wave resonators and filters for applications above 2 GHz

Bulk acoustic wave (BAW) devices are of interest for applications at higher microwave frequencies above 2 GHz. As frequencies increase, BAW devices require thinner films which decreases processing times and makes the technology more cost effective. However, the area of resonators and associated filters also decreases and begins to impact device performance and packaging requirements. This paper summarizes the technical requirements of BAW devices in the 2 to 20 GHz frequency range and shows specific results for resonators, ladder filters, and stacked crystal filters operating up to 20 GHz.