Patent ID: 6504453
Filing Date: 2003-01-07
Classification: H03H

Abstract:
A transversal surface acoustic wave filter comprising:a piezoelectric substrate including an input side and an output side; an interdigital transducer on the input side and an interdigital transducer on the output side arranged in the surface acoustic wave propagation direction on the piezoelectric substrate; and a reflector disposed outside of one of the interdigital transducer on the input side and the interdigital transducer on the output side in the surface acoustic wave propagation direction, the interdigital transducer adjacent to the reflector being weighted; wherein while a surface acoustic wave passes through the interdigital transducer adjacent to the reflector and while the surface acoustic wave reflecting from the reflector passes through the interdigital transducer on the output side, the surface acoustic wave is converted to first and second electrical signals, respectively, and the interval between the reflector and the interdigital transducer adjacent to the reflector is arranged such that no phase difference is generated between the first and second electrical signals; and the interdigital transducer adjacent to the reflector being weighted so that a portion of the interdigital transducer having the highest excitation intensity is positioned on the reflector side thereof.