Acoustic wave devices

摘要

In an acoustic wave device having a pair of spaced apart reflectors forming a resonant cavity, each reflector consists of an array of parallel reflective elements. At least one of the reflectors is weighted not by simple withdrawal of reflecting elements from a nominal uniform array but instead by substituting reflective elements of the uniform array with elements providing both net-zero reflection at required positions and also at least partial compensation for the velocity perturbation which would be produced by such simple withdrawal. Such weighting may be used to suppress the side lobes of the reflector response and hence improve the stopband performance of the acoustic wave device and, for example, a coupled resonator filter in which that device is incorporated.