Filter using piezoelectric material

摘要

A filter includes a piezoelectric substrate, and interdigital transducers (IDTs) that are formed on the piezoelectric substrate. At least one of the IDTs has a main electrode finger pattern that is weighted. The IDT having the main electrode finger pattern also has a sub electrode finger pattern that is connected in parallel to the main electrode finger pattern, and generates a surface acoustic wave that cancels a surface acoustic wave caused by leakage electric fields generated in the main electrode finger pattern.