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:
Jun. 26, 2007
Filed:
May. 19, 2005
Matthew A. Wetzel, San Diego, CA (US);
Harry S. Harberts, San Marcos, CA (US);
Paul L. Rodgers, Solana Beach, CA (US);
Matthew A. Wetzel, San Diego, CA (US);
Harry S. Harberts, San Marcos, CA (US);
Paul L. Rodgers, Solana Beach, CA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
A circuit and corresponding method for doubling the frequency of an input signal, even when the input signal is of low frequency or a square wave. The input signal is applied to a phase-shifting circuit that produces a pair of output signals that are theoretically 90° apart in phase, but may lack the desired form if the original input signal is of low frequency. The waveforms of the two output signals are enhanced in latching hysteresis buffers that produce more uniformly squared waves, with zero crossings corrected to be more exactly 90° apart and with desirably steep state transitions. The enhanced-waveform output signals are coupled to an exclusive OR (XOR) gate to produce a double-frequency output.