Optimal cut for saw devices on langasite

A method for forming a surface acoustic wave device comprising the steps of:

• providing a lanthanum gallium silicate (langasite) single crystal;
• orientating the crystal for cutting a planar surface, the crystal orientating defined by Euler angles .phi., 74 , and .psi.;
• cutting the crystal for forming the planar surface, the cut defined by the Euler angles, wherein .phi. has a value ranging from approximately -15.degree. to approximately 10.degree., .theta. has a value ranging from approximately 120.degree. to approximately 165.degree., and .psi. has a value ranging from approximately 20.degree. to approximately 45.degree.;
• and
• affixing an interdigitized transducer on the surface for propagating and detecting surface acoustic waves propagating in a direction generally along an axis of propagation defined relative to the crystal orientation angle .psi..

A method for forming a surface acoustic wave device substrate comprising the steps of:

• providing a lanthanum gallium silicate (langasite) single crystal;
• orientating the crystal for cutting a planar surface, the crystal orientating defined by Euler angles .phi., .theta., and .psi.;
• and
• cutting the crystal for forming the planar surface, the cut defined by the Euler angles, wherein .phi. has a value ranging from approximately -15.degree. to approximately 10.degree., .theta. has a value ranging from approximately 120.degree. to approximately 165.degree., and .psi. has a value ranging from approximately 20.degree. to approximately 45.degree. for affixing interdigitized transducer electrodes on the surface for propagating and detecting surface acoustic waves in a direction generally along an axis of propagation defined relative to the crystal orientation angle .psi..

A method for generally improving temperature stability, lowering power flow angle, and reducing diffraction in a surface acoustic wave device, the method comprising the steps of:

• providing a lanthanum gallium silicate (langasite) single crystal;
• orientating the crystal for cutting a planar surface, the crystal orientating defined by Euler angles .phi., .theta., and .psi.;
• cutting the crystal for forming the planar surface, the cut defined by the Euler angles, wherein .phi. has a value ranging from approximately -15.degree. to approximately 10.degree., .theta. has a value ranging from approximately 120.degree. to approximately 165.degree., and .psi. has a value ranging from approximately 20.degree. to approximately 45.degree.;
• and
• affixing interdigitized transducers on the surface for propagating and detecting surface acoustic waves in a direction generally along an axis of propagation defined relative to the crystal orientation angle .psi., and wherein electrodes of the transducers are generally perpendicular to the axis of propagation.