High-Q FBAR filters in a wafer-level chip-scale package

Wafer-level chip-scale packaged RF filters use thin-film bulk acoustic resonator technology. The 1/spl times/1mm/sup 2/ high-Q filter is hermetically sealed as two thin layers of silicon. The full-band 1900 MHz Tx filter mounted in a PCS power module has a 12 MHz roll-off, and replaces external split-band SAW filters and their accompanying switches.

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