| 摘要 |
PURPOSE:To achieve low loss easily and economically, by attaching an insulating film having a smaller lateral wave speed than that of a piezoelectric substrate on the non-electrode part of a transducer, in a rub-wave type surface wave device. CONSTITUTION:Input and output transducers 20 consisting of cross finger electrodes are provided on the surface of a piezoelectric substrate to constitute a surface wave device transmitting and receiving rub-wave type surface waves, and an insulating film 30 having smaller transversal wave speed than that of the piezoelectric substrate is attached to a non-electrode part between cross finger electrodes of the transducer 20. The same insulating film 30 is attached on a transmission path between the input and output transducers on the non-electrode part of the transducers 20, allowing to make further lower loss. |
