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. 18, 2006
Filed:
Aug. 27, 2004
William B. Ashley, Carlsbad, CA (US);
William B. Ashley, Carlsbad, CA (US);
AEA Technology Inc., Vista, CA (US);
Abstract
Impedance of an unknown load is determined by applying a reference signal from a signal generator through a multi-position switch to the unknown load, a first known calibration impedance, and second known impedance, which can be an open circuit, while measuring the complex voltage developed across each load. The source impedance of the signal generator can be determined from the measurements of the known impedances, and then the unknown impedance can be calculated, using complex voltage divider relationships. The reference signal is applied at one or more frequencies of interest and is preferably a sine wave. Impedance is measured accurately at all frequencies and the limitations of prior art frequency dependant directional-coupler methods of impedance measurement are overcome. The impedance measurement device can be incorporated into a handheld device with a keypad and display.