SAW and BAW technologies for RF filter applications: A review of the relative strengths and weaknesses

Acoustic filter technologies based on piezoelectric materials play a key role in wireless communication as they guarantee spectral integrity of RF signals. SAW filters have been used for this purpose since the early days of mobile phones. BAW filters are a relatively recent addition to the technology portfolio. Each technology claims to have unique advantages over the other. This paper gives a detailed review of the strength and weaknesses for both technologies. The aspects covered include process complexity, unique features, performance parameters and limitations. The application space for RF filters will be mapped out to identify areas where either SAW or BAW dominates or where they compete. Both technologies follow a steep path of improvements which involves introducing new materials, processes and design methods. Rivalry put aside there are many areas where advanced SAW and BAW can benefit from each other.