A filter includes a plurality of series portions each including one or more series resonators, and a plurality of shunt portions each including one or more shunt resonators. At least one of the plurality of shunt portions includes two shunt resonators connected to each other in anti-series, and antiresonance frequencies of the two shunt resonators are arranged externally of a passband.

A communication system using a single crystal acoustic resonator device. The device includes a piezoelectric substrate with a piezoelectric layer formed overlying a transfer substrate. A topside metal electrode is formed overlying the substrate. A topside micro-trench is formed within the piezoelectric layer. A topside metal with a topside metal plug is formed within the topside micro-trench. First and second backside cavities are formed within the transfer substrate under the topside metal electrode. A backside metal electrode is formed under the transfer substrate, within the first backside cavity, and under the topside metal electrode. A backside metal plug is formed under the transfer substrate, within the second backside cavity, and under the topside micro-trench. The backside metal plug is connected to the topside metal plug and the backside metal electrode. The topside micro-trench, the topside metal plug, the second backside cavity, and the backside metal plug form a micro-via.

Filter devices and methods are disclosed. A filter device includes a substrate having a surface. A back surface of a single-crystal piezoelectric plate is attached to the surface of the substrate, portions of the single-crystal piezoelectric plate forming a plurality of diaphragms spanning respective cavities in the substrate. A conductor pattern is formed on a front surface of the piezoelectric plate, the conductor pattern including a plurality of interdigital transducers (IDTs) of a plurality of resonators. Interleaved fingers of at least a first IDT of the plurality of IDTs are disposed on a diaphragm having a first thickness, and interleaved fingers of at least a second IDT of the plurality of IDTs are disposed on a diaphragm having a second thickness less than the first thickness.

A family of composite resonator devices having improved performance properties for use in electronic circuits. Each composite device includes two or more resonator electrodes on a single crystal or other resonant material. The two resonators may be connected in series or parallel, based on application requirements. The two resonators have different surface areas or some other type of asymmetry, causing the response of the composite device to have suppressed spurious modes, reduced insertion loss, or both. This is accomplished by designing the electrodes to have different frequency response curves, where the responses can be tuned and combined to reduce undesirable modes. Improvements in acceleration sensitivity and temperature sensitivity are also achieved. Both physically-applied and projected electrode types are disclosed, along with several crystal shapes. The family of composite resonator devices includes both passive and active devices, such as resonators, filters and oscillators.

An acoustic resonator filter package includes an acoustic resonator including a piezoelectric layer, a first electrode disposed on a first surface of the piezoelectric layer, and a second electrode disposed on a second surface of the piezoelectric layer; a first substrate having an upper surface on which the acoustic resonator is disposed, the first substrate comprising a first coupling member surrounding the acoustic resonator; a filter spaced apart from the acoustic resonator in an upward direction; a second substrate having a lower surface on which the filter is disposed, the second substrate including a second coupling member disposed above the first coupling member; and a connection member connecting the first coupling member and the second coupling member to each other, the connection member being made of a material different from a material of which the first coupling member and the second coupling member are made.

Hybrid filters and more particularly filters having acoustic wave resonators (AWRs) and lumped component (LC) resonators and packages therefor are described. In an example, a packaged filter includes a package substrate, the package substrate having a first side and a second side, the second side opposite the first side. A first acoustic wave resonator (AWR) device is coupled to the package substrate, the first AWR device comprising a resonator. A plurality of inductors is in the package substrate.

A piezoelectric material is described. The piezoelectric material comprises aluminum nitride (AlN) doped with ytterbium (Yb), an atomic percentage of Yb in the AlN being greater than or equal to approximately 10.0% and less than or equal to approximately 27.0%. Piezoelectric layers comprising the piezoelectric material may be used in bulk acoustic wave (BAW) acoustic resonators, and surface acoustic wave (SAW) acoustic resonators. The BAW acoustic resonators and SAW acoustic resonators can be used in a variety of applications.

Disclosed is a radio frequency multiplexer having an M number of multiplexer branches each having an outer port terminal coupled to a common outer node, wherein M is a positive counting number. Each of the M number of multiplexer branches comprises a multi-bandpass filter configured to filter an N number of bands multiplexed by the radio frequency multiplexer to pass an individual group of N/M bands, wherein N is a positive counting number greater than one and equal to a total number of bands to be multiplexed. Each of the M number of multiplexer branches further includes an N/M number of resonator branches each having a band port terminal configured to pass a single band and an inner branch terminal coupled to an inner port terminal of the multi-bandpass filter at a common inner node.

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.

Filter devices and methods are disclosed. A filter device includes a substrate and a piezoelectric plate attached to the substrate, the piezoelectric plate forming diaphragms spanning respective cavities in the substrate. A first portion of the piezoelectric plate has a first thickness. A front surface of a second portion of the piezoelectric plate is recessed relative to a front surface of the first portion of the piezoelectric plate such that the second portion of the piezoelectric plate has a second thickness less than the first thickness. A conductor pattern is formed on the front surfaces of the first and second portions of the piezoelectric plate. The conductor pattern includes a first interdigital transducer (IDT) with interleaved fingers on a diaphragm having the first thickness, and a second IDT with interleaved fingers on a diaphragm having the second thickness.