Patent ID: 6172580
Filing Date: 2001-01-09
Classification: H03H

Abstract:
A surface acoustic wave filter comprising:an input terminal;an output terminal;a series arm including at least one series resonator located between the input and output terminals;a parallel arm including at least one parallel resonator located between the series arm and a reference potential;a piezoelectric substrate; anda plurality of one-port surface acoustic wave resonators disposed on said piezoelectric substrate and arranged to define said at least one series resonator and said at least one parallel resonator, each of the plurality of one-port surface acoustic wave resonators including an interdigital transducer having a plurality of electrode fingers and at least two bus bars connected to the electrode fingers; whereina gap length between a first of the at least two bus bars of the interdigital transducer of at least one of the plurality of one-port surface acoustic wave resonators and a tip of one of the plurality of electrode fingers connected to a second of the at least two bus bars disposed opposite to the first of the at least two bus bars has a value of up to about 1.0 .lambda. in which .lambda. represents the wave length of a surface acoustic wave.