Abstract: A system includes a tunable bulk acoustic wave (BAW) resonator device and a direct-current (DC) tuning controller coupled to the tunable BAW resonator device. The system also includes an oscillator circuit coupled to the tunable BAW resonator device. The DC tuning controller selectively adjusts a DC tuning signal applied to the tunable BAW resonator device to adjust a signal frequency generated by the oscillator circuit.

Abstract: A method and a band reject filter (BRF) using as acoustic resonators at least one of bulk acoustic wave (BAW) resonators and film bulk acoustic resonators (FBAR) are provided. The BRF includes at least one substrate having at least one of a plurality of capacitors formed thereon, the plurality of capacitors having capacitances selected to achieve a particular band reject response. The BRF also includes at least one die. At least one of a plurality of acoustic wave resonators are formed thereon. The plurality of acoustic wave resonators are one of BAW resonators and FBARs and are designed to have the same resonant frequency. A plurality of conductors between the substrate and the die are positioned to electrically connect the acoustic wave resonators and the capacitors.

Abstract: A front end module (FEM) for a 5.6 GHz Wi-Fi acoustic wave resonator RF filter circuit. The device can include a power amplifier (PA), a 5.6 GHz resonator, and a diversity switch. The device can further include a low noise amplifier (LNA). The PA is electrically coupled to an input node and can be configured to a DC power detector or an RF power detector. The resonator can be configured between the PA and the diversity switch, or between the diversity switch and an antenna. The LNA may be configured to the diversity switch or be electrically isolated from the switch. Another 5.6 GHZ resonator may be configured between the diversity switch and the LNA. In a specific example, this device integrates a 5.6 GHz PA, a 5.6 GHZ bulk acoustic wave (BAW) RF filter, a single pole two throw (SP2T) switch, and a bypassable LNA into a single device.

Abstract: A filter circuit includes a first input node and a second input node for receiving an input signal, and a first output node and a second output node for providing an output signal. A first series acoustic resonator is coupled in series between the first input node and the first output node. At least one coupled resonator filter (CRF) includes first and second transducers, which may be acoustically coupled to one another. The first transducer has a first electrode coupled to the first input node, a second electrode coupled to the second input node, and a first piezoelectric layer between the first electrode and the second electrode. A second transducer has a third electrode coupled to the first output node, a fourth electrode coupled to the second output node, and a second piezoelectric layer between the third electrode and the fourth electrode.

Abstract: RF circuitry, which includes a first acoustic RF resonator (ARFR) and a first compensating ARFR, is disclosed. A first inductive element is coupled between the first compensating ARFR and a first end of the first ARFR. A second inductive element is coupled between the first compensating ARFR and a second end of the first ARFR. The first compensating ARFR, the first inductive element, and the second inductive element at least partially compensate for a parallel capacitance of the first ARFR.

Abstract: A tunable filter using acoustic resonators is disclosed. A tunable filter includes a plurality of tunable resonator units (20). Each tunable resonator unit (20) has acoustic wave resonators (12). Each acoustic wave resonator is associated with a different tunable frequency. Each tunable resonator unit also has a first switch (22) configured to select one of the plurality of acoustic wave resonators of the tunable resonator unit at a time. The first switches of the plurality of tunable resonator units are coupled to cooperatively select one acoustic wave resonator in each one of the plurality of tunable resonator units, where a selected acoustic wave resonator in a tunable resonator unit of the plurality of tunable acoustic resonator units is associated with a same tunable frequency response as the other selected acoustic resonators of the others of the plurality of tunable acoustic resonator units. The selection results in an overall tunable frequency response.

Abstract: A filter circuit includes a first input node and a second input node for receiving an input signal, and a first output node and a second output node for providing an output signal. A first series acoustic resonator is coupled in series between the first input node and the first output node. At least one coupled resonator filter (CRF) includes first and second transducers, which may be acoustically coupled to one another. The first transducer has a first electrode coupled to the first input node, a second electrode coupled to the second input node, and a first piezoelectric layer between the first electrode and the second electrode. A second transducer has a third electrode coupled to the first output node, a fourth electrode coupled to the second output node, and a second piezoelectric layer between the third electrode and the fourth electrode.

Abstract: Acoustic filters and methods are disclosed. A single-crystal piezoelectric is attached to a substrate, portions of the piezoelectric plate forming one or more diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators, interleaved fingers of each of the plurality of IDTs disposed on a respective diaphragm of the one or more diaphragms. A first frequency setting dielectric layer having a first thickness is disposed over the fingers of the IDTs of a first subset of the plurality of resonators. A second frequency setting dielectric layer having a second thickness greater than the first thickness is disposed over the fingers of the IDTs of a second subset of the plurality of resonators, wherein the first subset and the second subset are not identical.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A variable filter includes a serial arm resonator and a parallel arm resonance circuit, the parallel arm resonance circuit includes a parallel arm resonator and a capacitance element connected to the parallel arm resonator, the serial arm resonator and the parallel arm resonator respectively include IDT electrodes each formed of a plurality of electrode fingers formed on a substrate, and a film thickness of the plurality of electrode fingers of the parallel arm resonator is larger than a film thickness of the plurality of electrode fingers of the serial arm resonator.

Abstract: An elastic wave device includes a piezoelectric substrate, and elastic wave elements on the piezoelectric substrate and including IDT electrodes, respectively. The IDT electrode of a first of the elastic wave elements includes first and second busbars, and the IDT electrode of a second of the elastic wave elements includes third and fourth busbars. The second busbar and the third busbar extend parallel or substantially parallel to each other, and are spaced by a gap in a direction perpendicular or substantially perpendicular to an elastic-wave propagating direction. Each of the second and third busbars includes first and second electrode layers at least a portion of which is laminated on the first electrode layer. The second electrode layer of the second busbar is cut in at least one location in a direction crossing the elastic-wave propagating direction.

Abstract: A filter includes a series arm resonator, a first parallel arm resonance circuit, and a second parallel arm resonance circuit. The first parallel arm resonance circuit includes: a first parallel arm resonator connected to a first node; a first capacitor and a first switch connected together in parallel and connected in series with the first parallel arm resonator; and a first inductor provided on a path connecting the node and ground to each other via the first switch. The second parallel arm resonance circuit includes: a second parallel arm resonator connected to a second node; a second capacitor and a second switch connected together in parallel and connected in series with the second parallel arm resonator; and a second inductor provided on a path connecting the second node and ground to each other via the second switch. The first and second inductor have different inductance values.

Abstract: A filter circuit includes a first input node and a second input node for receiving an input signal, and a first output node and a second output node for providing an output signal. A first series acoustic resonator is coupled in series between the first input node and the first output node. At least one coupled resonator filter (CRF) includes first and second transducers, which may be acoustically coupled to one another. The first transducer has a first electrode coupled to the first input node, a second electrode coupled to the second input node, and a first piezoelectric layer between the first electrode and the second electrode. A second transducer has a third electrode coupled to the first output node, a fourth electrode coupled to the second output node, and a second piezoelectric layer between the third electrode and the fourth electrode.

Abstract: An elastic wave device includes a piezoelectric substrate and an interdigital transducer electrode on the piezoelectric substrate, the piezoelectric substrate including a piezoelectric layer and a high-acoustic-velocity member layer, the piezoelectric layer being stacked on the high-acoustic-velocity member layer. The piezoelectric layer is made of lithium tantalate. Denoting an elastic wave propagation direction as a first direction, and a direction perpendicular or substantially perpendicular to the first direction as a second direction, a central region, low-acoustic-velocity regions, and high-acoustic-velocity regions are provided in the interdigital transducer electrode in the second direction. The low-acoustic-velocity regions include mass-adding films on electrode fingers.

Abstract: A filter includes a series arm resonator, a first parallel arm resonance circuit and a second parallel arm resonance circuit. The each of the first parallel arm resonance circuit and the second parallel arm resonance circuit includes: a parallel arm resonator that is connected to a node; a pair of elements consisting of a capacitor and a switch, which are connected in parallel with each other, that is connected in series with the parallel arm resonator; and an inductor that is provided on a path that connects the node and ground to each other via the switch. The inductance value of the inductor of the first parallel arm resonance circuit and the inductance value of the inductor of the second parallel arm resonance circuit are substantially equal to each other.