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:
Aug. 04, 1998
Filed:
Jan. 22, 1996
James Gregory Mittel, Boynton Beach, FL (US);
Scott Humphreys, Boynton Beach, FL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A frequency synthesizer (100) is utilized for producing an output signal (124) which is phase locked to a reference signal (110) operating at a reference frequency. The frequency synthesizer (100) comprises a main phase lock loop (PLL) (102), and a tracker PLL (128). The main PLL (102) includes a phase detector (112), two frequency dividers (108, 126), a loop filter (116), a notch filter (118), and a controlled oscillator (122). The tracker PLL (128) phase locks to the reference signal (110), and biases the notch filter (118) in order to maintain an accurate lock on the notch frequency which is proportional to the reference frequency. All circuits are integrated in the same monolithic device in order to track parametric tolerances such as transconductances of the operational transconductance devices included in the tracker PLL (128) and the notch filter (118).