A band elimination filter includes a plurality of parallel resonators, each including a piezoelectric substrate and an IDT electrode on a surface of the piezoelectric substrate. The IDT electrode includes a pair of comb-shaped electrodes opposing each other, and the IDT electrode includes electrode fingers, a pitch of the electrode fingers being different between an end portion of the IDT electrode in a propagation direction of an elastic wave and a central portion of the IDT electrode different from the end portion.

A SAW element configured to suppress spurious emissions resulting from non-periodicity of an IDT electrode finger arrangement. In one example, the SAW element is a resonator comprising an IDT electrode including a first plurality of IDT electrode fingers connected to a first busbar and a second plurality of IDT electrode fingers connected to a second busbar, and reflectors having a plurality of reflector fingers. The pluralities of first and second IDT electrode fingers are alternatively connected to each busbar by either normal connections or reversed connections and include regions arranged by at least two different types of pitches. The normal connections are such that either the odd-numbered or even-numbered IDT electrode fingers connect to the first busbar, and the reversed connections are such that the opposite group of IDT electrode fingers connect to the first busbar.

Aspects and embodiments disclosed herein include a die comprising a plurality of surface acoustic wave resonators. At least one of the plurality of surface acoustic wave resonators has an aperture that at least partially overlaps an aperture of at least one other of the plurality of surface acoustic wave resonators. The at least one of the plurality of surface acoustic wave resonators includes interdigital transducer electrodes with interdigital transducer electrode fingers having a first average pitch and reflector electrodes with reflector electrode fingers having at least two different pitches. Each of the at least two different pitches are greater than the first average pitch.