An acoustic resonator filter includes: a series unit including at least one series acoustic resonator electrically connected, in series, between first and second ports configured to pass a radio frequency (RF) signal; a first shunt unit disposed on a first shunt connection path between the at least one series acoustic resonator and a ground, the first shunt unit including a plurality of shunt acoustic resonators connected to each other in series and having different resonance frequencies; and a second shunt unit disposed in a second shunt connection path between the at least one series acoustic resonator and the ground, the second shunt unit including at least one shunt acoustic resonator and having higher inductance than inductance of the first shunt unit.

A ladder type acoustic wave filter is disclosed. The acoustic wave filter can include a plurality of parallel arm resonators and a plurality of series arm resonators, in which an electromechanical coupling coefficient of a parallel arm resonator closest to an input node of the acoustic wave filter among the plurality of parallel arm resonators can be smaller than an electromechanical coupling coefficient of a series arm resonator closest to the input node among the plurality of series arm resonators.

Embodiments of the invention include a piezoelectric package integrated filtering device that includes a film stack. In one example, the film stack includes a first electrode, a piezoelectric material in contact with the first electrode, and a second electrode in contact with the piezoelectric material. The film stack is suspended with respect to a cavity of an organic substrate having organic material and the film stack generates an acoustic wave to be propagated across the film stack in response to an application of an electrical signal between the first and second electrodes.

In accordance with an embodiment, an RF system includes a transmit path having a first tunable transmit band stop filter, and a power amplifier coupled to an output of the first tunable transmit band stop filter, where the first tunable transmit band stop filter is configured reject a receive frequency and pass a transmit frequency; a receive path comprising an LNA; and a duplex filter having a transmit path port coupled to an output of the power amplifier, a receive path port coupled to an input of the LNA, and an antenna port, where the duplex filter is configured to pass the transmit frequency and reject the receive frequency between the antenna port and the transmit path port, pass the receive frequency and reject the transmit frequency between the antenna port and the receive path port.

An acoustic wave filter includes a substrate having voids formed therein; a first resonator disposed on one or more of the voids, and a second resonator disposed on other of the voids. A first trimming layer is provided in the first resonator, and a second trimming layer is provided in the second resonator. The second trimming layer is formed of a material having an etching rate for a given etchant different from that of the first trimming layer.

A thin-film bulk acoustic resonator, a semiconductor apparatus including the acoustic resonator and its manufacturing methods are presented. The thin-film bulk acoustic resonator includes a lower dielectric layer, a first cavity inside the lower dielectric layer, an upper dielectric layer, a second cavity inside the upper dielectric layer, and a piezoelectric film that is located between the first and the second cavities and continuously separates these two cavities. The plan views of the first and the second cavities have an overlapped region, which is a polygon that does not have any parallel sides. The piezoelectric film in this inventive concept is a continuous film without any through-hole in it, therefore it can offer improved acoustic resonance performance.

A filter with bulk acoustic wave devices is disclosed. The filter includes a first bulk acoustic wave resonator and a second bulk acoustic wave resonator. The first bulk acoustic wave resonator includes a first raised frame structure. The first raised frame structure is a multi-layer raised frame structure. The second bulk acoustic wave resonator includes a second raised frame structure. The first raised frame structure has at least one more raised frame layer than the second raised frame structure.

An acoustic resonator filter includes: a series unit including at least one series acoustic resonator electrically connected, in series, between first and second ports configured to pass a radio frequency (RF) signal; a first shunt unit disposed on a first shunt connection path between the at least one series acoustic resonator and a ground, the first shunt unit including a plurality of shunt acoustic resonators connected to each other in series and having different resonance frequencies; and a second shunt unit disposed in a second shunt connection path between the at least one series acoustic resonator and the ground, the second shunt unit including at least one shunt acoustic resonator and having higher inductance than inductance of the first shunt unit.

Bulk acoustic wave resonators of two or more different filters can be on a common die. The two filters can be included in a multiplexer, such as a duplexer, or implemented as standalone filters. With bulk acoustic wave resonators of two or more filters on the same die, the filters can be implemented in less physical space compared to implementing the same filters of different die. Related methods, radio frequency systems, radio frequency modules, and wireless communication devices are also disclosed.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode facing each other across at least a part of the piezoelectric film; and an insertion film that is inserted between the lower electrode and the upper electrode, is located in an outer peripheral region within a resonance region where the lower electrode and the upper electrode face each other across the piezoelectric film, is located in a region that is located outside the resonance region and surrounds the resonance region, is not located in a center region of the resonance region, and includes a first part, which is located in the resonance region and has a first film thickness, and a second part, which is located outside the resonance region and has a second film thickness, the first film thickness being less than the second film thickness.