| 摘要 |
PROBLEM TO BE SOLVED: To provide a device having sharp frequency characteristics by arranging a first reflector for forming the reflection wave of phase almost opposite to the phase of a surface acoustic wave(SAW) excited by an IDT and a second reflector for forming the reflection wave of phase almost equal with the phase of the SAW excited by the IDT in order from the side of the IDT. SOLUTION: In the SAW excited from an input IDT 20 to both left and right sides, an excited wave 51 to be propagated to left is received by an output IDT 10 and converted to an electric signal. On the other hand, one part of an excited wave 52 to be propagated to right becomes a reflection wave 53 reflected by a first reflector 30. The reflection wave 53 reflected by the first reflector 30 is received by the output IDT 10 and the reflection wave 53 reflected by the first reflector 30 becomes the relation of phase opposite to the excited wave 51 to be propagated to left. One part of an excited wave 52 to be propagated to right becomes a reflection wave 54 reflected by a second reflector 40 and is received by the output IDT 10. The reflection wave 54 reflected by the second reflector 40 becomes the relation of phase opposite to the reflection wave 53 reflected by the first reflector 30.
|
