A resonator element for use in a filter is provided. The resonator element includes a first resonator acoustically coupled to a second or third resonator or both. The first resonator has terminals for incorporation in a filter structure. A tuning circuit is coupled to the second or third resonator or both to enable tuning of the resonator element. The tuning circuit includes a variable capacitor and an inductor.

Acoustic resonator devices and filters; and methods of their fabrication are disclosed. A piezoelectric plate is bonded to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity that is formed in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a back surface of an interposer, the second conductor pattern including a second plurality of contact pads. The interposer is formed by cofiring layers of thin ceramic tape, at least one layer of the tape comprising printed conductors. A plurality of conductive balls is formed on and directly bonds the first plurality of contact pads to respective contact pads of the second plurality of contact pads.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a surface of a base, the second conductor pattern including a second plurality of contact pads. Each pad of the first plurality of contact pads is connected to a respective pad of the second plurality of contact pads. A seal is formed between a perimeter of the piezoelectric plate and a perimeter of the base.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer disposed on the diaphragm, and a first plurality of contact pads. A second conductor pattern is formed on a back surface of an interposer, the second conductor pattern including a second plurality of contact pads. The interposer has layers of a LTCC circuit card, at least one layer of the tape comprising printed conductors. A plurality of conductive balls directly bonds the first plurality of contact pads formed on the plate to respective contact pads of the second plurality of contact pads formed on the interposer.

Acoustic resonator devices and filters are disclosed. A piezoelectric plate is attached to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a chip cavity in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer on the diaphragm, and first contact pads. An interposer has walls on its back surface that are attached to the chip front surface and that surround the diaphragm. An interposer cover layer spans the walls creating an enclosed interposer cavity over the diaphragm. A second conductor pattern formed on the walls and cover layer includes second contact pads on the interposer back surface. Electrical connections between the second contact pads and connection points on the chip electrically connect the first contact pads to respective ones of the second contact pads.

Acoustic resonator devices and filters; and methods of their fabrication are disclosed. A piezoelectric plate is bonded to a substrate, a portion of the piezoelectric plate forming a diaphragm spanning a cavity that is formed in the substrate. A first conductor pattern is formed on a surface of the piezoelectric plate. The first conductor pattern includes interleaved fingers of an interdigital transducer on the diaphragm, and first contact pads. Walls of an interposer back surface are formed onto the resonator front surface and surround the diaphragm. An interposer cover layer is formed on the walls, spans the walls and creates an enclosed interposer cavity over the diaphragm. A second conductor pattern is formed on the walls and cover layer that includes second contact pads on the interposer back surface; and connections that electrically connect the first contact pads to respective ones of the second contact pads.

In accordance with an embodiment, a method of operating an RF system includes filtering a first wideband RF signal using a wideband filter bank. Filtering the first RF signal includes separating the first wideband RF signal into frequency cluster signals, where each frequency cluster signal of the frequency cluster signals includes different frequency ranges, the first wideband RF signal includes multiple RF bands, and each of the different frequency ranges comprises a plurality of RF bands of the multiple RF bands. The method further includes band stop filtering at least one of the frequency cluster signals to produce a band stopped frequency cluster signal.

Embodiments may relate to a radio frequency (RF) front-end module (FEM) that includes an acoustic wave resonator (AWR) die. The RF FEM may further include an active die coupled with the package substrate of the RF FEM. When the active die is coupled with the package substrate, the AWR die may be between the active die and the package substrate. Other embodiments may be described or claimed.

Embodiments may relate to a radio frequency (RF) front-end module (FEM) that includes an acoustic wave resonator (AWR) die. The RF FEM may further include an active die coupled with the package substrate of the RF FEM. When the active die is coupled with the package substrate, the AWR die may be between the active die and the package substrate. Other embodiments may be described or claimed.

A piezoelectric thin film resonator includes: a piezoelectric film located on a substrate; lower and upper electrodes facing each other across a part of the piezoelectric film; and an insertion film located between the lower and upper electrodes, located in a part of an outer peripheral region within a resonance region where the lower and upper electrodes face each other across the piezoelectric film, and not located in a center region of the resonance region, a first width in the resonance region of the insertion film in a first region, where the upper electrode is extracted from the resonance region, being greater than a third width in the resonance region in a third region other than a second region, where the lower electrode is extracted from the resonance region, and the first region, a second width in the resonance region in a second region being the third width or greater.