PIW/SAW multistrip coupler working at Bragg conditions

A multistrip coupler (MSC) is one of the most important device in SAW technology. It couples two acoustic channels in SAW filters and resonators. The analysis presented here concerns primarily the later application generalized to piezoelectric interfacial waves (PIWs). In Bragg conditions, the reflection of PIWs or SAWs from MSC strips is the reason for severe distortion of its frequency characteristic and cannot be neglected in the analysis. A rigorous theory of MSC is developed accounting for both electric, and mechanical interactions of MSC strips with the SAW that results in Bragg reflection from the strips. Bulk waves are neglected.