Methods and apparatus for analyzing periodic waveforms
US4301404A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 1980 |
| Grant date | Nov 17, 1981 |
| Priority date | — |
| Expiry date | Feb 6, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A waveform to be analyzed is repetitively sampled at corresponding instants in each of several cycles, and the samples from each cycle for a respective instant summed to derive an average value for that instant in one cycle of the waveform. The average values are then used for Fourier transform analysis, either by mathematical manipulation or by sequential correlation. The timing of the samples is determined by counting pulses from a high-frequency clock for one cycle of the waveform, truncating the count to remove the n least significant digits, and taking a sample every time a number of pulses equal to the truncated count has occurred (resulting in 2.sup.n samples per cycle for a modulo 2 counter).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.