Low-distortion waveform generating method and waveform generator using the same
US5113139A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 11, 1991 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Apr 11, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06J1/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Waveform data read out of a memory is converted by a D/A converter into an analog waveform, and amplified by an amplifier to generate a waveform signal. To cancel a distortion generated in the amplifier, a composite waveform composed of a distortion canceling signal waveform and a fundamental frequency signal waveform to be generated is written into the memory. To determine a distortion canceling signal, the fundamental frequency component in the signal waveform is attenuated by a notch filter. The signal waveform is then converted by an A/D converter into a digital multi-sine waveform. This waveform is input to a computation and control part and subjected to a Fourier transform analysis to compute the amplitude and phase of each harmonic component. Further, the output of the amplifier the memory, is fed via the notch filter and the A/D is input to the computation and control part, where it is subjected to a Fourier transform analysis to compute the amplitude and phase of each distortion component. At the same time, the output of the amplifier is converted into digital waveform data without being applied to the notch filter and the data is subjected to a Fourier transform analysis …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.