X-band thin film acoustic filters on GaAs

The semiconductor bulk acoustic resonator (SBAR) is composed entirely of thin films, piezoelectric aluminum nitride, and metal electrode films (primarily aluminum). The authors describe the performance of an SBAR filter which has only 6.1 dB insertion loss at 7.8 GHz (2nd harmonic) and 7.5 dB insertion loss at 11.6 GHz (third harmonic), with fractional bandwidths less than 1%. This filter demonstrates that SBAR technology is practical for X-band filters in MMICs (monolithic microwave integrated circuits).<
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