Contour resonator

1. A contour resonator at least including a first vibrating substrate and a second vibrating substrate, the first vibrating substrate and the second vibrating substrate having main surfaces facing each other, the main surfaces being bonded, the contour resonator comprising:

a first excitation electrode provided on a front main surface of the first vibrating substrate;

a second excitation electrode provided on a back main surface of the second vibrating substrate; and

a common intermediate excitation electrode provided at an interface between the first vibrating substrate and the second vibrating substrate, wherein:

the first excitation electrode and the second excitation electrode are electrically connected to constitute a first terminal;

the intermediate excitation electrode constitutes a second terminal; and

the first vibrating substrate and the second vibrating substrate perform a contour vibration in accordance with an excitation signal applied between the first terminal and the second terminal, wherein

a resonance frequency Fb of a single body of at least one vibrating substrate of the first vibrating substrate or the second vibrating substrate and a resonance frequency Fe of a single body of at least one excitation electrode of the first excitation electrode, the second excitation electrode or the intermediate excitation electrode satisfy a relationship of 0.995×Fe≦Fb≦1.005×Fe;

the contour resonator is a Lame-mode resonator or a pseudo-Lame mode resonator:

the first vibrating substrate and the second vibrating substrate are each made of a crystal having crystal anisotropy; and

the first vibrating substrate and the second vibrating substrate are identical to each other in cut angle of the crystal and different from each other in in-plane rotation angle by 90°, or the first vibrating substrate and the second vibrating substrate are different from each other in a cut angle from the crystal by 180° and identical to each other or different from each other in in-plane rotation angle by 180°.

2. The contour resonator according to claim 1 , wherein:

the first vibrating substrate and the second vibrating substrate are each made of a rectangular quartz crystal substrate;

a cut angle of one quartz crystal substrate of the first vibrating substrate and the second vibrating substrate is represented as YXltφ/θ of IRE standards; and

a cut angle of an other quartz crystal substrate is represented as YXltφ/θ+90°, YXltφ/θ−90°, YXltφ+180°/θ, YXltφ+180°/θ+180°, YXlt 100 +180°/θ−180°, YXltφ−180°/θ, YXltφ−180°/θ+180° or YXltφ−180°/θ−180°.

3. The contour resonator according to claim 2 , wherein 40°≦θ≦50°, −50°≦θ≦−40°, 130°≦θ≦140° or −140°≦θ≦−130° is satisfied.

4. The contour resonator according to claim 1 , wherein: the contour resonator is a Lame-mode resonator, wherein:

the first excitation electrode is divided by n (n is an integer of 2 or more) in a planar direction;

the intermediate excitation electrode and the second excitation electrode are divided by n to face the first excitation electrode; and

one of n-divided excitation electrodes adjacent to each other is connected to the first terminal and an other is connected to the second terminal.

5. The contour resonator according to claim 1 , wherein the contour resonator is a contour shear resonator, wherein:

the first vibrating substrate and the second vibrating substrate are each made of a crystal having crystal anisotropy; and

the first vibrating substrate and the second vibrating substrate are identical to each other in cut angle of the crystal and different from each other in in-plane rotation angle by 90°, or

the first vibrating substrate and the second vibrating substrate are different from each other in cut angle from the crystal by 180° and identical to each other or different from each other in in-plane rotation angle by 90°.