Fabrication and Characteristics of High Frequency SAW Filler

고주파 SAW Filter 의 제작과 Filter 특성

  • 이동욱 (영남대학교 대학원 전자공학과) ;
  • 김동수 (영남대학교 대학원 센서 및 시스템공학과) ;
  • 강성건 (포항산업과학연구원 전력전자연구팀) ;
  • 류근걸 (포항산업과학연구원 전력전자연구팀) ;
  • 남효덕 (영남대학교 공대 전자공학과) ;
  • 이만형 (경북대학교 대학원 센서공학과)
  • Published : 1997.11.01

Abstract

SAW filters of transversal type were fabricated on some piezoelectric substrates of the LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$Y-X, Quartz ST-cut wafers through the simulation in which the number o: IDT and window function were changed for the required frequency, and the mask making. Their IDT spacing and width were 3 ${\mu}{\textrm}{m}$, chip size was 4.462 $\times$ 2.086 mm$^2$, and they had double electrode transversal type IDTs. In addition to pure Al electrode devices, Ti thin films having the different thicknesses was introduced between the Al electrode and the substrate for improving the power resistance strength. They had 11-12 dB insertion losses similar to those of pure Al electrode SAW filters in case of LN 128$^{\circ}$ Y-X, LN 64$^{\circ}$ Y-X, meaning that Ti thin film was not detrimental to the insertion loss and general frequency properties. The filters had the center frequencies 162MHz for LN 128$^{\circ}$ Y-X, 186MHz for 64$^{\circ}$ Y-X, and 131MHz for Quartz ST-cut substrates.

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