| 摘要 |
PURPOSE:To attain broad band and low loss with simple structure by making the interval of plural gratings constituting a reflector uneven. CONSTITUTION:A surface acoustic wave propagated from an electrode 12 in two directions is reflected totally at the reflectors 14, 16 where plural gratings are arranged unevenly so as to provide a desired band characteristic. The wave is propagated toward the reflectors 15, 17 while its propagating direction is changed by 90 deg. and the surface acoustic wave touching the reflectors 15, 17 is changed for the propagating direction again by 90 deg. and reaches a reception electrode 13. |
