Wideband complex radio frequency impedance measurement
US7030627B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 27, 2004 |
| Grant date | Apr 18, 2006 |
| Priority date | — |
| Expiry date | Aug 27, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.