Patent ID: 6437662
Filing Date: 2002-08-20
Classification: H03H

Abstract:
A surface acoustic wave filter comprising:a Y-cut X-propagation LiTaO3 substrate having a cut angle of about 38 degrees to about 46 degrees; at least first and second series arm surface acoustic wave resonators provided on the substrate and connected in series to define a series arm; and at least one parallel arm surface acoustic wave resonator provided on the substrate and connected to the series arm; wherein each of the first and second series arm surface acoustic wave resonator includes an interdigital transducer having a plurality of pairs of electrode fingers, and a number of pairs of the electrode fingers of the first series arm surface acoustic wave resonator is represented by N (N=a natural number), the corresponding number of the second series arm surface acoustic wave resonator differs from nÃ—N (n=a natural number),such that the size of ripples in pass band is reduced.