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.

Embodiments of this disclosure relate to bulk acoustic wave resonators on a substrate. The bulk acoustic wave resonators include a first bulk acoustic wave resonator, a second bulk acoustic wave resonator, a conductor electrically connecting the first bulk acoustic wave resonator to the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate.

Multiplexing circuits with bulk acoustic wave (BAW) resonators as network elements for higher performance are provided. Multiplexing networks which support newer fourth generation (4G) and fifth generation (5G) standards may include a combination of multiplexers having a number of radio frequency (RF) filters connected to an antenna at the same time. One critical aspect of such a multiplexer design is the loading of these filters to each other, in which the static capacitance presented by a filter can be beneficial or detrimental to other filters in the multiplexing network. Aspects of the present disclosure introduce a BAW resonator to improve multiplexing network performance using the frequency-dependent capacitance, resonance, and/or anti-resonance of the BAW resonator.

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 5.170 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.

The invention provides a filter device, an RF front-end device and a wireless communication device. The filter device comprises a substrate, at least one resonance device, a passive device and a connector, wherein the at least one resonance device has a first side and a second side opposite to the first side, the substrate is located on the first side, and the passive device is located on the second side. The at least one resonance device is connected to the passive device through the connector. The RF filter device formed by integrating the resonance device (such as an SAW resonance device or a BAW resonance device) and the passive device (such as an IPD) in one die can broaden the passband width, has a high out-of-band rejection, and occupies less space in an RF front-end chip.

An RF triplexer 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.

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.

Filter circuitry is used in communication systems that employ multiple antennas. In general, a communication system may have a transmit path and a receive path. The transmit path extends to a first antenna port and is configured to present signals for transmission in a first communication band and a second communication band to the first antenna port for transmission via a first antenna that is coupled to the first antenna port. The receive path extends to a second antenna port and comprises a first multiple passband/multiple stopband filter that provides a plurality of passbands and a plurality of stopbands interleaved with one another, wherein a first stopband and a second stopband of the plurality of stopbands correspond respectively to the first communication band and the second communication band and are separated by a first passband of the plurality of passbands.

Acoustic wave devices are disclosed. An acoustic wave device can include a first filter and a second filter coupled to a common node. The second filter includes acoustic wave resonators of a first type (e.g., bulk acoustic wave resonators) and a series acoustic wave resonator of the second type (e.g., a surface acoustic wave resonator) that is coupled between the acoustic wave resonators of the first type and the common node. The acoustic wave device can further include a loop circuit coupled to the first filter, in which the loop circuit is configured to generate an anti-phase signal to a target signal at a particular frequency. In certain embodiments, the first filter is a receive filter and the second filter is a transmit filter.

A filter device having a pass band and a stop band on a lower frequency side than the pass band includes a filter having a pass band including the pass band, a series arm resonator connected in series to the filter, a first inductor directly connected in series to the series arm resonator, and a parallel arm resonator connected between a node on a path connecting the filter and the series arm resonator and the ground. The parallel arm resonator constitutes a resonance circuit having a resonant frequency at which an attenuation pole corresponding to a high frequency end of the first stop band, and the series arm resonator and the inductor constitute a resonance circuit having an anti-resonant frequency on a lower frequency side than the pass band and having a sub-resonant frequency higher than a resonant frequency of the resonance circuit.