COMPOSITE ELASTIC SURFACE WAVE FILTER

摘要

PURPOSE:To ensure an extreme increment of the guaranteed attenuation quantity without increasing the outer measurement of the filter but by forming the elastic surface wave filter and other filters on the same substrate and then giving the serial connection between them. CONSTITUTION:The elastic surface wave filter consisting of comb-line electrode 1 and 2 plus other filters 6 and 7 are provided at the end part of piezoelectric substrate 5 which does not affect the propagation of the elastic surface wave. Then filters 6 and 7 are connected in series to filters 1 and 2. As a result, the guaranteed attenuation quantity can be increased extremely without increasing the outer measurement of the filter.