Resonant circuit sensor of multiple properties of objects
US4257001A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 13, 1979 |
| Grant date | Mar 17, 1981 |
| Priority date | — |
| Expiry date | Apr 13, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/28
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention is a resonant circuit sensor of physical properties of objects that monitors measurable properties of resonant circuits affected by interactions of the objects with the polarized, resonant oscillations of the circuits. The circuits can be passive with excitation by an external energy source or active with a source included as an integral part. Simultaneous or sequential sensing of more than one physical property of objects is obtained by detecting resonant oscillation characteristics such as amplitude, frequency, phase or polarization and by detecting quantities influenced by such characteristics for one or more orientations of the objects relative to the polarization of the oscillations. These resonant oscillations can be in the form of electromagnetic fields, electric fields, magnetic fields, or acoustic waves. For electromagnetic fields in the microwave frequency range, device structures, such as Gunn device flanges, that have current and voltage properties that depend on microwave signal properties can provide versatile output signals for the sensor. The sensing can be relative and detect differences in object properties and it can be absolute and measure values f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.