Technique for widening the temperature range of surface acoustic wave reflection array filters
US4210883A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1978 |
| Grant date | Jul 1, 1980 |
| Priority date | — |
| Expiry date | Jun 27, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02653
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
For widening the temperature range of a reflective array device configured on a substrate having an anisotropic temperature coefficient of delay, such as ST-quartz material, so that the signal strength does not decrease appreciably as the temperature of the device is changed over a broad range, the structural shape of the reflective array is configured such that the reflection angles of the discontinuity-creating surface structure vary across the reflecting edges of the discontinuity stripe (e.g. groove or rib) pattern. In one embodiment, the stripe pattern of the grating may be varied so that the reflection angles vary for alternating stripes. In another embodiment, opposite edges of a stripe may be non-parallel so that the reflection angles vary for each stripe. It is also possible to amplitude weight the frequency response characteristic of a grating by controlling the physical structure of the individual stripes of which a grating pattern is formed. The use of a dot array configuration is especially advantageous in this regard since amplitude weighting can be achieved simply by controlling the dot array density of each stripe, implemented in a straightforward manner by suitable…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.