Method for ascertaining the harmonic components of an analog electrical signal at a fundamental frequency which changes over time
US8108167B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 2008 |
| Grant date | Jan 31, 2012 |
| Priority date | — |
| Expiry date | Jul 20, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method includes ascertaining harmonic components of a periodic analog signal at a fundamental frequency which changes over time. The signal is digitized and fast Fourier transformed. A target signal is produced by modulating the signal using a first carrier frequency to form two frequency sidebands, the first carrier frequency being greater than the fundamental frequency of the signal. One of the two frequency sidebands of the modulated signal is filtered. The filtered frequency sideband is modulated using a second carrier frequency forming two frequency sidebands. The second carrier frequency is greater than the fundamental frequency of the signal. The difference between the second and first carrier frequencies is the same as the difference between the fundamental frequency and the target fundamental frequency. One of these two frequency sidebands is output as the target signal to calculate the fast Fourier transformation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.