An acoustic wave component is disclosed. The acoustic wave component can include a bulk acoustic wave resonator and a surface acoustic wave device. The bulk acoustic wave resonator can include a first portion of a ceramic substrate, a first piezoelectric layer positioned on the ceramic substrate, and electrodes positioned on opposing sides of the first piezoelectric layer. The surface acoustic wave device can include a second portion of the ceramic substrate, a second piezoelectric layer positioned on the ceramic substrate, and an interdigital transducer electrode on the second piezoelectric layer.

A multiplexer includes: a first chip that has a first filter and a resonator, the first filter being connected between a common terminal and a first terminal, a first end of the resonator being connected to the common terminal not via the first filter; and a second chip that has a second filter, the second filter being connected between a second end of the resonator and a second terminal and having a pass band lower than that of the first filter, a resonance frequency of the resonator being higher than the pass band of the second filter.

A circuit having a power amplifier port, an antenna port, and a ladder network coupled between the power amplifier and antenna ports is disclosed. The ladder network includes a proximal series acoustic resonator coupled to the power amplifier port, a distal series acoustic resonator coupled to the antenna port, and at least one series acoustic resonator coupled between the proximal series acoustic resonator and the distal series acoustic resonator. A first shunt acoustic resonator is coupled between a fixed voltage node and the proximal series acoustic resonator and the at least one series acoustic resonator. A second shunt acoustic resonator is coupled between the fixed voltage node and a second node to which the at least one series acoustic resonator is also coupled. A first inductor is coupled in parallel with the proximal series acoustic resonator to create notches below and above a passband of the ladder network.

Techniques for improving acoustic resonators and resonator structures are disclosed, including filters, oscillators and systems that may include such devices. A bulk acoustic wave (BAW) resonator may comprise a substrate. The bulk acoustic wave (BAW) may further comprise a plurality of piezoelectric layers including first, second, third and fourth piezoelectric layers acoustically coupled with one another and arranged over the substrate. The first, second, third and fourth piezoelectric layers may have respective piezoelectric axis orientations. The first, second, third and fourth piezoelectric layers may have respective thicknesses. Electromechanical coupling of the bulk acoustic wave (BAW) resonator may, but need not be limited.

A multiplexer includes a filter (10) arranged between a common terminal and an input/output terminal (110) and configured to pass a radio frequency signal in a first frequency band, and a filter (20) arranged between the common terminal and an input/output terminal (120) and configured to pass a radio frequency signal in a second frequency band. The filter includes series arm circuits (31 and 32) connected in series, a series arm circuit (33) connected in parallel to the series arm circuit (32), and a parallel arm circuit. The series arm circuit (32) includes a series arm resonator that is an acoustic wave resonator. The series arm circuit (33) includes a switch arranged on a second path connecting nodes. In a CA mode, the switch is OFF. In a non-CA mode, the switch is ON.

Aspects of this disclosure relate to methods of manufacturing bulk acoustic wave components. Such methods include plasma dicing to singulate individual bulk acoustic wave components. A buffer layer can be formed over a substrate of bulk acoustic wave components such that streets are exposed. The bulk acoustic wave components can be plasma diced along the exposed streets to thereby singulate the bulk acoustic wave components

A filter device has a substrate with a first cavity and a second cavity on a single die; and a bonding layer formed on the substrate but not spanning the first cavity or the second cavity. A piezoelectric plate is bonded to the bonding layer and spans the first and the second cavity. However, excess portions of piezoelectric plate are removed that extend a certain length past the perimeter of the first cavity and of the second cavity. Excess portions may be piezoelectric material that extends in the length and width direction past the perimeter of a cavity by more than between 2 and 25 percent of the cavity perimeter. An interdigital transducer (IDT) is on a front surface of the piezoelectric plate and having interleaved fingers over the first cavity.

A multi-stage matching network filter circuit device. The device comprises bulk acoustic wave (BAW) resonator device having an input node, an output node, and a ground node. A first matching network circuit is coupled to the input node. A second matching network circuit is coupled to the output node. A ground connection network circuit coupled to the ground node. The first or second matching network circuit can include an inductive ladder network including a plurality of series inductors in a series configuration and a plurality of grounded inductors wherein each of the plurality of grounded inductors is coupled to the connection between each connected pair of series inductors. The inductive ladder network can include one or more LC tanks, wherein each of the one or more LC tanks is coupled between a connection between a series inductor and a subsequent series inductor, which is also coupled to a grounded inductor.

Radio frequency filters are disclosed. A filter includes a first transversely-excited film bulk acoustic resonator (XBAR) having a first sub-resonator and a second sub-resonator connected in parallel. A pitch of the first sub-resonator is not equal to a pitch of the second sub-resonator and/or a mark of the first sub-resonator is not equal to a mark of the second sub-resonator.

A resonator element for use in a filter is provided. The resonator element includes a first resonator acoustically coupled to a second resonator. The first resonator has terminals for incorporation in a filter structure. A tuning circuit is coupled to the second resonator to enable tuning of the resonator element.