Abstract: Aspects of the disclosure relate to devices, wireless communication apparatuses, methods, and circuitry implementing bulk wave suppression in a stacked electroacoustic device. One aspect includes a first substrate comprising a first surface and a second surface, where the second surface is opposite the first surface, a first AW resonator circuit positioned on the first surface of the first substrate, a plurality of elements including a first element, where the plurality of elements are positioned on the second surface of the first substrate, and where the first element is aligned with the first AW resonator circuit, and a second substrate comprising a first surface and a second surface, where the plurality of elements are positioned on the first surface of the second substrate, and where the plurality of elements create a cavity between the first substrate and the second substrate.

Abstract: A stacked AW filter package includes a first substrate stacked on a second substrate. The first substrate has a first AW filter circuit on first surface and a metal layer on a second surface. The second substrate has a second AW filter circuit disposed in a cavity between the metal layer of the first substrate and a third surface of the second substrate. The metal layer is coupled to the second AW filter circuit by a metal interconnect formed in a metallization layer on a side surface of the first substrate. The metal layer provides isolation to reduce cross-talk (e.g., electromagnetic interference) within the stacked AW filter package between the first AW filter circuit and the second AW filter circuit. Including the metal layer in the stacked AW filter package improves signal quality of transmitted and received signals filtered in the first and second AW filter circuits.

Abstract: A filter circuit comprises a main operating unit (MU) arranged in the series signal line providing most of the filter function of the filter circuit. A micro acoustic last series resonator (RLs) as a last element of the main operating unit in the series signal line is prone to excite a spurious mode that is damped with a final series capacitance (CEs) circuited between the last element and the antenna terminal (AT).