Analysis of Ladder Filters based on Solidly Mounted Resonators with Aluminum Nitride Thin Film

Abstract

$T$- and U-shared links of ladder filters based on microelectronic BAW resonators with a Bragg reflector are considered. The BAW resonator with a piezoelectric aluminum nitride thin film operated at a frequency of 3.7 GHz and has a quality factor of 518 is fabricated. The analytical studies of the electrical characteristics of ladder filters are presented. It is shown that ladder filter with a relative bandwidth of the order of 1 % can be obtained based on the resonators with resonance bandwidth equal to 10…15 MHz. The minimum insertion loss of the ladder filter is -2.9 dB. The maximum guaranteed attenuation in the stopband at 5 % offset is -41.4 dB for a U-shared link with three BAW resonators.