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:
Feb. 01, 1994
Filed:
Mar. 30, 1992
Robert B Stokes, Torrance, CA (US);
Kei-fung Lau, Harbor City, CA (US);
James Chung-Kei Lau, Torrance, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
This invention discloses a semiconductor bulk acoustic resonator including at least one thin film piezoelectric layer positioned on a semiconductor substrate. The acoustic resonator includes a heating ring positioned around the outer perimeter of the piezoelectric layer in order to heat the piezoelectric layer to a desirable elevated temperature. A heat sensing film fabricated on the piezoelectric layer monitors the temperature of the piezoelectric layer such that the heating ring maintains the piezoelectric layer at a constant temperature. By this, an oscillator circuit using this semiconductor bulk acoustic resonator as the frequency controlling element can maintain a constant frequency over a wide range of temperatures which may affect frequency stability.