Three terminal type piezoelectric filter
AssigneeMurata Manufacturing Co., Ltd.
InventorJiro Inoue
Life of this patent
Estimating the term…
Abstract
A piezoelectric filter of three terminal type which includes a piezoelectric substrate having one main surface at its one face and the other main surface at its other surface, an input electrode and an output electrode respectively provided on the one main surface of the piezoelectric substrate and a common electrode provided on the other main surface of the piezoelectric substrate. The output electrode is provided so as to face or confront the input electrode in a spaced relation from the input electrode, while the common electrode is arranged selectively not to confront, or to confront, to a certain extent at its peripheral edge portion, the output electrode through the piezoelectric substrate.
Claims12
A piezoelectric filter of three terminal type which is especially adapted to vibrate primarily in an expansion mode, said filter comprising:
- a piezoelectric substrate having first and second opposed main surfaces;
- an input electrode and an output electrode respectively provided on said first main surface of said piezoelectric substrate;
- and
- a common electrode provided on said second main surface of said piezoelectric substrate, said common electrode confronting less than the entire said output electrode through said piezoelectric substrate whereby spurious edge mode vibrations which would otherwise be excited are suppressed.
A piezoelectric filter of three terminal type which is especially adapted to vibrate primarily in an expansion mode, said filter comprising:
- a piezoelectric substrate having first and second opposed main surfaces;
- an input electrode and an output electrode respectively provided on said first main surface of said piezoelectric substrate, said output electrode being spaced from said input electrode;
- and
- a common electrode provided on said second main surface of said piezoelectric substrate, said common electrode confronting less than the entire said output electrode through said piezoelectric substrate whereby spurious edge mode vibrations which would otherwise be excited are supressed.
A piezoelectric filter of three terminal type which is especially adapted to vibrate primarily in an expansion mode, said filter comprising:
- a piezoelectric substrate of a parallelogram configuration having first and second opposed main surfaces;
- an input electrode and an output electrode respectively provided on said first main surface of said piezoelectric substrate, said input electrode also having a parallelogram configuration and provided in the vicinity of the central portion of said first main surface, and said output electrode being provided adjacent to peripheral edges of said first main surface in a concentrically spaced relation with respect to said input electrode;
- and
- a common electrode provided on said second main surface of said piezoelectric substrate, said common electrode having a parallelogram configuration and confronting less than the entire said output electrode through said piezoelectric substrate whereby spurious edge mode vibrations which would otherwise be excited are suppressed.
A piezoelectric filter of three terminal type which is especially adapted to vibrate primarily in an expansion mode, said filter comprising:
- a piezoelectric substrate of a parallelogram configuration having first and second opposed main surfaces;
- an input electrode and an output electrode respectively provided on said first main surface of said piezoelectric substrate, said input electrode having a rectangular configuration and provided at one side of said first main surface so as to face said output electrode also having a rectangular configuration and provided at the other side of said first main surface in a spaced relation from said output electrode;
- and
- a common electrode provided on said second main surface of said piezoelectric substrate, said common electrode having a rectangular configuration and confronting less than the entire said output electrode through said piezoelectric substrate whereby spurious edge mold vibration which would otherwise be excited are suppressed.
Dependencies are inferred from the claim text.