S.A.W. filters: some case histories

The paper presents the background to s.a.w. (surface-acoustic-wave) filter design by discussion of both the basic consideration and the second-order design problems. The state of the art in filters available from a production activity is described by reference to three examples: the t.v. filter, the c.a.t.v. filter and some radar filters. In each case, the important criteria are discussed and their impact on the design detail is stressed. The future direction of s.a.w. filter work is briefly reviewed for each example.