Nonsynchronous scattering loss in surface‐acoustic‐wave reflective‐array‐compression filters

摘要

Nonsynchronous scattering of the incident surface wave by topographic reflecting grooves into bulk and surface waves is identified as a significant loss mechanism in surface‐acoustic‐wave reflective array devices. Since scattering loss is groove‐depth and therefore position dependent, the resulting loss characteristic differs from that which applies to propagation loss. A phenomenological model is presented for predicting the effect of this scatttering loss on the passband of large time‐bandwidth (TB) product reflective‐array‐compression (RAC) filters. The importance of correctly modeling the scattering loss is demonstrated using a 16 200 : 1 RAC filter as an example.