A method of fabricating a configurable single crystal acoustic resonator (SCAR) device integrated circuit. The method includes providing a bulk substrate structure having first and second recessed regions with a support member disposed in between. A thickness of single crystal piezo material is formed overlying the bulk substrate with an exposed backside region configured with the first recessed region and a contact region configured with the second recessed region. A first electrode with a first terminal is formed overlying an upper portion of the piezo material, while a second electrode with a second terminal is formed overlying a lower portion of the piezo material. An acoustic reflector structure and a dielectric layer are formed overlying the resulting bulk structure. The resulting device includes a plurality of single crystal acoustic resonator devices, numbered from (R1) to (RN), where N is an integer greater than 1.

RF filtering circuitry comprises a first node, a second node, and a series signal path between the first node and the second node. A number of acoustic resonators are coupled to one or more of the first node and the second node via the series signal path. A first one of the acoustic resonators is associated with a first quality factor and a first electromechanical coupling coefficient. A second one of the acoustic resonators is associated with a second quality factor and a second electromechanical coupling coefficient. The first quality factor is different from the second quality factor and the first electromechanical coupling coefficient is different from the second electromechanical coupling coefficient.

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.

A front-end module may include an acoustic wave filter with a first and second interdigital transducer electrode. The first interdigital transducer electrode may be single-ended with a first input bus bar that receives an input signal and a second input bus bar connected to ground. The second interdigital transducer electrode may be differential with a first output bus bar connected to a first output terminal and a second output bus bar connected to a second output terminal. The front-end module may include a low noise amplifier (LNA) that outputs a differential signal via a differential output and has a differential input connected to the acoustic wave filter. The LNA may include a first input transistor that receives a first signal from the first output terminal of the acoustic wave filter and a second input transistor that receives a second signal from the second output terminal of the acoustic wave filter.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A radio frequency (RF) extractor includes: a first bandpass filter electrically connected between a shared antenna port and a first RF port, disposed in a first chip, and having a first passband; a second bandpass filter electrically connected between the shared antenna port and a second RF port, and disposed in a second chip, and having a second passband; a first notch filter electrically connected to the shared antenna port, disposed in the first chip, and having a first stopband partially overlapping the first passband; and a second notch filter electrically connected to the shared antenna port, disposed in the second chip, and having a second stopband partially overlapping the second passband.

An RF filter system including a plurality of BAW resonators arranged in a circuit, the circuit including a serial configuration of resonators and a parallel shunt configuration of resonators, the circuit having a circuit response corresponding to the serial configuration and the parallel configuration of the plurality of bulk acoustic wave resonators including a transmission loss from a pass band having a bandwidth from 5.490 GHz to 5.835 GHz. Resonators include a support member with a multilayer reflector structure; a first electrode including tungsten; a piezoelectric film including aluminum scandium nitride; a second electrode including tungsten; and a passivation layer including silicon nitride. At least one resonator includes at least a portion of the first electrode located within a cavity region defined by a surface of the support member.

A bulk-acoustic resonator module includes: a module substrate; a bulk-acoustic resonator connected to the module substrate by a connection terminal and disposed spaced apart from the module substrate; and a sealing portion sealing the bulk-acoustic resonator. The bulk-acoustic resonator includes a resonating portion disposed opposite to an upper surface of the module substrate. A space is disposed between the resonating portion and the upper surface of the module substrate.

A ladder filter comprises a plurality of series arm bulk acoustic wave resonators electrically connected in series between an input port and an output port of the ladder filter and a plurality of shunt bulk acoustic wave resonators electrically connected in parallel between adjacent ones of the plurality of series arm bulk acoustic wave resonators and ground, at least one of the plurality of shunt bulk acoustic wave resonators including raised frame regions having a first width, at least one of the plurality of series arm bulk acoustic wave resonators having one of raised frame regions having a second width less than the first width or lacking raised frame regions.