Capacitively coupled dc voltage switchable barium strontium titanate solidly mounted resonator filter

A dc voltage switchable barium strontium titanate solidly mounted bulk acoustic wave capacitively coupled resonators filter has been demonstrated for the first time. The filter consists of two switchable bulk acoustic wave solidly mounted resonators coupled with a high-Q barium strontium titanate capacitor. The resonators have a measured loaded series and parallel quality factors of 135 and 87 in the on-state (30V), respectively. The electromechanical coupling coefficient of the resonators is 6.34 % in the on-state (30V). The insertion loss and return loss of the filter is -3.66 dB and -13.74 dB, respectively.