The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 02, 2008
Filed:
Dec. 16, 2003
Werner Ruile, Munich, DE;
Ulrike Roesler, Hebertshausen, DE;
Ulrich Wolff, Munich, DE;
Anton Leidl, Hohenbrunn, DE;
Gerd Scholl, Munich, DE;
Markus Hauser, Feldafing, DE;
Ulrich Knauer, Munich, DE;
Werner Ruile, Munich, DE;
Ulrike Roesler, Hebertshausen, DE;
Ulrich Wolff, Munich, DE;
Anton Leidl, Hohenbrunn, DE;
Gerd Scholl, Munich, DE;
Markus Hauser, Feldafing, DE;
Ulrich Knauer, Munich, DE;
Epcos AG, Munich, DE;
Abstract
An apparatus including a piezoelectric substrate having at least one transducer electrode structure. The structure having a metallization formed by one or more metals with a mean specific density that is at least 50% higher than that of aluminum. The structure having a compensation layer that is applied fully or partially over the metallization. The compensation layer is of a material having a temperature dependence of elastic constants that counteracts the temperature coefficient of frequency of the substrate. The compensation layer has a thickness that is less than 15% of an acoustic wavelength of a wave capable of propagation in the structure.