Abstract: Disclosed is a Bulk Acoustic Wave (BAW) assist filter structure with a BAW resonator stacked onto an integrated passive device (IPD). In exemplary aspects disclosed herein, the BAW filter structure includes a transducer with electrodes and a piezoelectric layer between the electrodes. The IPD is electrically coupled to the BAW resonator and provides a high frequency of operation. In such a configuration, the BAW assist filter structure has a low insertion loss and mitigates electrical length parasitic loss due to the close electrically proximity of the BAW resonator stacked onto the IPD. Further, the BAW assist filter structure is able to filter high frequencies and provides improved filter performance and greater flexibility in design of a filter transfer function.

Abstract: Disclosed is a Bulk Acoustic Wave (BAW) assist filter structure with a BAW resonator stacked onto an integrated passive device (IPD). In exemplary aspects disclosed herein, the BAW filter structure includes a transducer with electrodes and a piezoelectric layer between the electrodes. The IPD is electrically coupled to the BAW resonator and provides a high frequency of operation. In such a configuration, the BAW assist filter structure has a low insertion loss and mitigates electrical length parasitic loss due to the close electrically proximity of the BAW resonator stacked onto the IPD. Further, the BAW assist filter structure is able to filter high frequencies and provides improved filter performance and greater flexibility in design of a filter transfer function.