SURFACE ACOUSTIC WAVE DEVICE

摘要

A surface acoustic wave filter having an unbalance-balance converting function and an impedance converting function and realizing a small surface acoustic wave device. An input interdigital transducer and an output interdigital transducer are arranged on a surface acoustic wave propagation path of a piezoelectric substrate and, assuming the intersection width of electrode fingers of the input or output interdigital transducer is X, the input or output transducer comprises two split interdigital transducers provided with electrode fingers having intersection width of about X/2. Two split interdigital transducers are connected in series with the electrodes of each electrode finger being led out therefrom and arranged such that the signals at two outputs or inputs connected with a pair of balance terminals have a phase difference of 180 DEG .