Apparatus and methods for spectral analysis of electrical materials, components and devices
US4991128A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1988 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | Aug 4, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/221
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Measurements of complex permittivity using transient techniques and Fourier transforms require computation which can be lengthy. In the invention, a synthesizer generates a succession of waveforms each containing a small number of harmonically related frequency components. These waveforms are applied to a capacitive potentiometer formed by a reference capacitor and a sample head. The voltages across the potentiometer and the sample head are passed by way of an analog-to-digital converter to a microprocessor which calculates Fourier transforms and indicates permittivity versus frequency. By limiting the frequency components, the computation time is reduced and a quick scan to find spectral regions of interest is possible. These regions can then be examined at higher resolution by changing a clock frequency which determines the generation of the frequency components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.