Surface wave devices with low passband ripple
US7023300B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Dec 15, 2004 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Jan 19, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/14567
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Very low passband ripple is provided in a wide bandwidth high frequency SAW FIR filter using slanted finger IDTs by one or more of three techniques: cancelling regenerated SAWs at parallel-connected input IDTs of two SAW filters which are similar except for a quarter-wavelength difference in spacing of the input and output IDTs, this difference varying with wavelength across the IDT aperture; shaping edges of shield electrodes to provide quarter-wavelength differences in, and hence cancellation of, SAWs reflected at the edges, the differences varying with wavelength across the IDT aperture; and making pairs of slanted shield electrodes symmetrical to compensate for refraction of SAWS by the shield electrodes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.