Surface wave filter using comb-shaped transducers including fingers weighted by variation of the length of overlap of these fingers

摘要

The invention relates to surface wave filters with weighted comb transducers. It consists in placing on the substrate 10 of a surface wave filter, between the input transducer 11 and output transducer 12, an acoustic waveguide 13 operating in monomode fashion. The transfer function of the filter is then equal to the product of the transfer functions of the two transducers. It allows the use of a weakly piezoelectric substrate. IMAGE