Surface acoustic wave systems and methods
US4620167A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 1985 |
| Grant date | Oct 28, 1986 |
| Priority date | — |
| Expiry date | May 9, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R23/17
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Dynamic variation of the functional properties of a surface acoustic wave (SAW) device is achieved by using photoconductive material on a wave propagating substrate and illuminating the material with changing light patterns. Photoconductive materials, such as lead sulfide or cadmium sulfide, are used that are essentially dielectrics and have substantially no effect on SAW propagation when not illuminated, but under suitable levels of illumination become resistive and interact with the electric fields of the waves to dissipate energy as heat. Scanning control of the areas of illumination may be used to attenuate sidelobes and scattering in a wideband system, while intensity variations may be used to amplitude modulate the waves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.