Method of modifying the temperature drift of the propagation time of surface elastic waves and a device obtained by said method
First Claim
1. A method of reducing the differences in propagation time of surface elastic waves ascribed to variations in temperature of a crystalline substrate propagating said surface elastic waves, said method comprising the steps of cutting the crystalline substrate in accordance with a predetermined crystal cut, and in subjecting at least one superficial zone of the substrate, located in the trajectory of said waves, to an ion bombardment;
- said ion bombardment permanently altering the regular lattice arrangement of the atoms of said crystalline substrate;
the intensity and the extent of said ion bombardment being adjusted for substantially reducing within given temperature and frequency ranges, said differences in propagation time.
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Abstract
The present invention relates to the modification of the temperature-induced drift in propagation time of surface elastic waves. The invention proposes to achieve this modification by selecting a suitable crystal cut of the crystalline substrate, and carrying out a localized ion bombardment of the surface at which the elastic waves propagate.
18 Citations
7 Claims
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1. A method of reducing the differences in propagation time of surface elastic waves ascribed to variations in temperature of a crystalline substrate propagating said surface elastic waves, said method comprising the steps of cutting the crystalline substrate in accordance with a predetermined crystal cut, and in subjecting at least one superficial zone of the substrate, located in the trajectory of said waves, to an ion bombardment;
- said ion bombardment permanently altering the regular lattice arrangement of the atoms of said crystalline substrate;
the intensity and the extent of said ion bombardment being adjusted for substantially reducing within given temperature and frequency ranges, said differences in propagation time. - View Dependent Claims (2, 3, 4, 5, 6)
- said ion bombardment permanently altering the regular lattice arrangement of the atoms of said crystalline substrate;
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7. An electromechanical surface wave device comprising a crystalline substrate;
- a superficial zone of the surface of said substrate being modified by an ion bombardment permanently altering the regular lattice arrangement of the atoms of said crystalline substrate;
said zone being located on the path of said surface wave for causing a modification of the thermal drift of the propagation time of said surface wave along said surface.
- a superficial zone of the surface of said substrate being modified by an ion bombardment permanently altering the regular lattice arrangement of the atoms of said crystalline substrate;
Specification