Capacitive tap weighted surface acoustic wave transducers

Abstract

A transducer for a surface acoustic wave device. In accordance with an embodiment of the invention, there is provided an acoustic wave propagating substrate and first and second spaced elongated conductive fingers disposed on the substrate. A layer of dielectric material is formed over the first and second fingers. A first electrode is formed on the dielectric layer above the first finger, the first electrode being proportioned to oppose a predetermined portion of the first finger. A second electrode is formed on the dielectric layer above the first finger, the second electrode being spaced from the first electrode and proportioned to oppose another predetermined portion of the first finger. A third electrode is formed on the dielectric layer above the second finger, the third electrode being proportioned to oppose a predetermined portion of the second finger. A fourth electrode is formed on the dielectric layer above the second finger, the fourth electrode being proportioned to oppose another predetermined portion of the second finger. A plurality of input/output (i.e., input or output) terminals are provided, and means are provided for coupling the input/output terminals to the electrodes.

Dependencies are inferred from the claim text.