Tunable film bulk acoustic resonators and filters
US10312882B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Jul 22, 2015 |
| Grant date | Jun 4, 2019 |
| Priority date | — |
| Expiry date | Jul 22, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2009/02196
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In wireless communications, many radio frequency bands are used. For each frequency band, there are two frequencies, one for transmitting and the other for receiving. As the band widths are small and separation between adjacent bands is also small, many band pass filters with different band pass frequencies are required for each communication unit such as mobile handset. The invention provides tunable film bulk acoustic resonators TFBARs containing semiconducting piezoelectric layers and methods for tuning and adjusting the resonant properties. When a DC biasing voltage is varied, both the depletion region thickness and neutral region thickness associated in the semiconducting piezoelectric layers varies leading to changes in equivalent capacitances, inductance and resistances and hence the resonance properties and frequencies. A plurality of the present TFBARs are connected into a tunable oscillator or a tunable and selectable microwave filter for selecting and adjusting of the bandpass frequency by varying the biasing voltages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.