Switchable and tunable composite film bulk acoustic wave resonators (CompFBAR)
Research Project, 2012 – 2014

The main objective of this project is experimental demonstration of composite Film Bulk Acoustic Resonators (FBAR) with frequency band switching and channel selection capabilities. Today?s mobile phones cover up to nine frequency bands using filter banks consisting of dedicated filters for each path. The number of bands expected to increase up to twenty causing size, performance and cost issues. Tuneable filters are recognised as the most promising way to meet these challenges. Current tuning technologies include semiconductor and ferroelectric varactors, MEM switches. None of these technologies meet all requirements of the tuneable filters used in microwave transceivers. At present the filters in mobile phones are based on FBAR and surface acoustic wave devices that are not tuneable. Tuneable FBARs using DC field induced piezoelectric effect in paraelectric phase ferroelectrics are proposed and patented (via Ericsson) by the proposer?s group. They meet requirements of the channel selection filters. However their tunability for frequency band selection is far from being useful. In this project the band switching and channel selection FBARs consist of stacked ferroelectric films. The polarisation in these films may have the same or opposite directions depending on the polarity of the controlling DC voltage. Frequency band switching is achieved by changing the polarities of the voltages applied to the films, the channel selection by changing their magnitudes


Spartak Gevorgian (contact)

Chalmers, Microtechnology and Nanoscience (MC2), Terahertz and Millimetre Wave Laboratory


Swedish Research Council (VR)

Project ID: 2011-4203
Funding Chalmers participation during 2012–2014


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