Optimal acoustic impedance materials for polished substrate coating to suppress passband ripple in BAW resonators and filters
US8512800B2 · kind B2 · utility
5Cited by
15References
9Claims
0Family size
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Key dates
| Filing date | Dec 4, 2007 |
| Grant date | Aug 20, 2013 |
| Priority date | — |
| Expiry date | Jan 7, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/175
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Methods of reducing phase and amplitude ripples in a BAW resonator frequency response by providing a substrate, fabricating a Bragg mirror having alternate layers of a high acoustic material and a low acoustic material on a first surface of the substrate, fabricating a BAW on the Bragg mirror, and coating a second side of the substrate opposite the first side with a lossy material having an acoustic impedance in the range of 0.01× to 1.0× the acoustic impedance of the layers of high impedance material, the second surface of the substrate being a polished surface. Various embodiments are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.