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:
Apr. 14, 1998
Filed:
May. 10, 1996
John H Spears, McHenry, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A reference oscillator (118) in a communication device (100) such as a radiotelephone is controlled by temperature compensating the reference oscillator (118). At the time of manufacture, characterizing data are stored in non-volatile memory (128) in the communication device (100). When the communication device (100) is powered up, the characterizing data are read and used to provide an initial correction (206) to the output frequency of the reference oscillator (118). Subsequently, an automatic frequency control operation is performed using the RF signal received from a remote transmitter as a reference signal. A frequency correction is determined (214) in the form of a frequency step size and step direction. The output frequency of the reference oscillator is repeatedly stepped until frequency error is minimized.