UNIDIRECTIONAL SURFACE ACOUSTIC WAVE FILTER AND ITS PRODUCTION

摘要: PROBLEM TO BE SOLVED: To increase the thickness of an electrode film serving as a reflector with addition mass and to improve reflection efficiency surface acoustic wave attain unidirectivity no complicated process nor accurate mask matching, etc., required by oxidizing part including obtain oxide increasing at compared other parts. SOLUTION: An interdigital 10 consists two bus bars 11 12 digitals 13 14 connected respectively. The width each 15 is set λ/8 3λ/8 Then such constitution includes double layer part. digital bar has single small thickness, films are formed on surfaces 12. Thus, have layers increased 13. also applying anodization processing aluminum electrode, so that coefficient can be changed large.