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:
Jul. 20, 2004
Filed:
Mar. 07, 2001
Todd E. Humes, Shoreline, WA (US);
Kenneth K. Tsai, Rancho Palos Verdes, CA (US);
Talley J. Allen, Torrance, CA (US);
Mark Kintis, Manhattan Beach, CA (US);
Northrop Grumman Corporation, Los Angeles, CA (US);
Abstract
Fast switching and fast settling is achieved in a phase locked loop (“PLL”) containing a bandwidth switched active loop filter ( ) by feeding the phase error signal of the phase detector ( ) of the PLL to the non-inverting input of the amplifier ( ) within the loop filter and having the electronic switch ( ) control the loop filter bandwidth through changing the resistance ( ) to ground at the inverting input of the amplifier between a high and low value associated respectively with broad bandwidth and narrow bandwidth to the loop filter. Switching is possible in as little as one microsecond, and is accompanied by fast settling of the loop with minimal generation of phase/frequency perturbation. The foregoing PLL is of particular benefit in fast switching frequency synthesizers, such as used in frequency hopping frequency synthesizers of frequency and time division multiplexing systems.