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 even-mode resonator filter is disclosed. The even-mode resonator filter is provided with high stability, and comprises: a first even-mode resonance module, a second even-mode resonance module, a first filter unit and a second filter unit. In the present invention, the first even-mode resonance module comprises a first resonance unit and a second resonance unit, and the second even-mode resonance module comprises a third resonance unit and a fourth resonance unit. By letting the second resonance unit be coupled to the first resonance unit as well as making the third resonance unit be coupled to the fourth resonance unit, the even-mode resonator filter of the present invention has the advantage of eliminating unexpected resonance.

A piezoelectric thin film resonator includes: a substrate; a lower electrode located on the substrate; a piezoelectric film that has a step on an upper surface thereof and is located on the lower electrode, a film thickness of the piezoelectric film inside the step being greater than a film thickness of the piezoelectric film outside the step; an upper electrode located on the piezoelectric film so that a resonance region is formed, the lower electrode and the upper electrode facing each other across the piezoelectric film in the resonance region, the resonance region including the step in plan view; and an insertion film located in the piezoelectric film, between the piezoelectric film and the lower electrode, or between the piezoelectric film and the upper electrode in at least a part of an outer peripheral region within the resonance region, and not located in a central region of the resonance region.

A piezoelectric thin film resonator includes: a substrate; a lower electrode located on the substrate; a piezoelectric film that has a step on an upper surface thereof and is located on the lower electrode, a film thickness of the piezoelectric film inside the step being greater than a film thickness of the piezoelectric film outside the step; an upper electrode located on the piezoelectric film so that a resonance region is formed, the lower electrode and the upper electrode facing each other across the piezoelectric film in the resonance region, the resonance region including the step in plan view; and an insertion film located in the piezoelectric film, between the piezoelectric film and the lower electrode, or between the piezoelectric film and the upper electrode in at least a part of an outer peripheral region within the resonance region, and not located in a central region of the resonance region.

Embodiments of the invention include an acoustic wave resonator (AWR) module. In an embodiment, the AWR module may include a first AWR substrate and a second AWR substrate affixed to the first AWR substrate. In an embodiment, the first AWR substrate and the second AWR substrate define a hermetically sealed cavity. A first AWR device may be positioned in the cavity and formed on the first AWR substrate, and a second AWR device may be positioned in the cavity and formed on the second AWR substrate. In an embodiment, a center frequency of the first AWR device is different than a center frequency of the second AWR device. In additional embodiment of the invention, the AWR module may be integrated into a hybrid filter. The hybrid filter may include an AWR module and other RF passive devices embedded in a packaging substrate.

Embodiments of the invention include an acoustic wave resonator (AWR) module. In an embodiment, the AWR module may include a first AWR substrate and a second AWR substrate affixed to the first AWR substrate. In an embodiment, the first AWR substrate and the second AWR substrate define a hermetically sealed cavity. A first AWR device may be positioned in the cavity and formed on the first AWR substrate, and a second AWR device may be positioned in the cavity and formed on the second AWR substrate. In an embodiment, a center frequency of the first AWR device is different than a center frequency of the second AWR device. In additional embodiment of the invention, the AWR module may be integrated into a hybrid filter. The hybrid filter may include an AWR module and other RF passive devices embedded in a packaging substrate.

A high-frequency module (10) includes a laminated substrate formed by laminating a plurality of insulator layers, a first terminal (P1) and a second terminal (P2) provided on the laminated substrate, a filter (20) connected between the first terminal (P1) and the second terminal (P2), a matching circuit (40) connected between the first terminal (P1) and the filter (20), and an inductor (60) provided as a conductor pattern in or on the laminated substrate, and connected between the filter (20) and the ground. The matching circuit (40) includes a mounting circuit unit (41) provided as an individual component on the laminated substrate, and a layer circuit (42) provided as a conductor pattern in or on the laminated substrate. A layer circuit unit (42) is electromagnetically coupled to the inductor (60).

A high-frequency module (10) includes a laminated substrate formed by laminating a plurality of insulator layers, a first terminal (P1) and a second terminal (P2) provided on the laminated substrate, a filter (20) connected between the first terminal (P1) and the second terminal (P2), a matching circuit (40) connected between the first terminal (P1) and the filter (20), and an inductor (60) provided as a conductor pattern in or on the laminated substrate, and connected between the filter (20) and the ground. The matching circuit (40) includes a mounting circuit unit (41) provided as an individual component on the laminated substrate, and a layer circuit (42) provided as a conductor pattern in or on the laminated substrate. A layer circuit unit (42) is electromagnetically coupled to the inductor (60).

An even-mode resonator filter is disclosed. The even-mode resonator filter is provided with high stability, and comprises: a first even-mode resonance module, a second even-mode resonance module, a first filter unit and a second filter unit. In the present invention, the first even-mode resonance module comprises a first resonance unit and a second resonance unit, and the second even-mode resonance module comprises a third resonance unit and a fourth resonance unit. By letting the second resonance unit be coupled to the first resonance unit as well as making the third resonance unit be coupled to the fourth resonance unit, the even-mode resonator filter of the present invention has the advantage of eliminating unexpected resonance.

An apparatus is disclosed for a bridge-type filter. In example aspects, the apparatus includes a filter circuit having a first port, a second port, and a filter core. The filter core is coupled between the first port and the second port. The filter core includes at least one transformer, a first resonator arrangement, and a second resonator arrangement. The first resonator arrangement is coupled to the at least one transformer and includes multiple acoustic resonators. The second resonator arrangement is coupled to the at least one transformer and includes multiple acoustic resonators.