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:
Jan. 30, 2007
Filed:
Mar. 04, 2005
Michael M. Driscoll, Woodstock, MD (US);
Karl M. Metzger, Westminster, MD (US);
Christopher R. Vale, Elkridge, MD (US);
Norman G. Matthews, Pasadena, MD (US);
Michael M. Driscoll, Woodstock, MD (US);
Karl M. Metzger, Westminster, MD (US);
Christopher R. Vale, Elkridge, MD (US);
Norman G. Matthews, Pasadena, MD (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
A crystal oscillator having a crystal filter with multiple crystals in a ladder configuration, resonant at a desired operating frequency. An oscillatory signal loop feedback path includes a voltage controlled phase shifter operable to shift the phase of the signal in the feedback loop in response to an applied control voltage. The feedback loop also includes a loop phase shift circuit to ensure that the feedback signal is a multiple of 360°, and a band pass mode selection circuit for eliminating unwanted frequencies.