A method and apparatus for a piezoelectric resonator having combined thickness and width vibrational modes are disclosed. A piezoelectric resonator may include a piezoelectric substrate and a first electrode coupled to a first surface of the piezoelectric substrate. The piezoelectric resonator may further include a second electrode coupled to a second surface of the piezoelectric substrate, where the first surface and the second surface are substantially parallel and define a thickness dimension of the piezoelectric substrate. Furthermore, the thickness dimension and the width dimension of the piezoelectric substrate are configured to produce a resonance from a coherent combination of a thickness vibrational mode and a width vibrational mode when an excitation signal is applied to the electrodes.