A radio-frequency module is provided that includes a structure, a filtering element disposed on the structure, a switching element embedded in the structure, and an impedance element connected to the switching element and the filtering element. In a plan view of the structure, the switching element and the filtering element overlap each other in at least part thereof. The structure has a plurality of vias including a via , a via and a via. The via connects the input-output terminal and the filtering element. The via connects the ground terminal and an impedance adjustment circuit including the switching element and the impedance element. In a plan view, the via is located in a smallest rectangular region encompassing the vias.

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.

A bulk acoustic resonator package includes a substrate, a cap, and first and second bulk acoustic resonators each including a first electrode, a piezoelectric layer, and a second electrode stacked in a direction in which the substrate and the cap face each other, and disposed between the substrate and the cap, wherein the first and second bulk acoustic resonators form a bandwidth based on first and second resonant frequencies different from each other and first and second antiresonant frequencies different from each other, a difference between the first and second resonant frequencies exceeds 200 MHz, the first bulk acoustic resonator is disposed closer to the substrate than to the cap, and the second bulk acoustic resonator is disposed closer to the cap than to the substrate.

An elastic wave includes a piezoelectric substrate having a polarization direction denoted by an arrow Px, and first and second IDT electrodes arranged on the substrate in an elastic wave propagation direction with a shared reflector therebetween. A first bus bar of the first IDT electrode and a first end portion bus bar of a second reflector are connected to a wiring electrode to define a first terminal. A second bus bar of the first IDT electrode and a second end portion bus bar of the shared reflector are connected to each other to define a second terminal. A first end portion bus bar and a first bus bar are electrically connected to each other. A second bus bar and a second end portion bus bar are electrically connected to each other, and the first and second IDT electrodes and are connected in parallel between the first and second terminals.

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.

An RF ladder filter having a parallel capacitance compensation circuit is disclosed. The parallel capacitance compensation circuit is made up of a first inductive element with a first T-terminal and a first end coupled to a first ladder terminal and a second inductive element with a second T-terminal that is coupled to the first T-terminal of the first inductive element and a second end coupled to a second ladder terminal. Further included is a compensating acoustic RF resonator (ARFR) having a fixed node terminal and a third T-terminal that is coupled to the first T-terminal of the first inductive element and the second T-terminal of the second inductive element, and a finite number of series-coupled ladder ARFRs, wherein the parallel capacitance compensation circuit is coupled across one of the finite number of series-coupled ARFRs by way of the first ladder terminal and the second ladder terminal.

An acoustic filter device for telecommunication devices includes a first acoustic band pass filter having a corresponding first passband and a second acoustic band pass filter having a corresponding second passband. The second acoustic band pass filter is connected in parallel with the first acoustic band pass filter to provide a combined passband including the first and second passbands.

A ladder type acoustic wave filter is disclosed. The acoustic wave filter can include a plurality of parallel arm resonators and a plurality of series arm resonators, in which an electromechanical coupling coefficient of a parallel arm resonator closest to an input node of the acoustic wave filter among the plurality of parallel arm resonators can be smaller than an electromechanical coupling coefficient of a series arm resonator closest to the input node among the plurality of series arm resonators.

A bulk acoustic resonator filter includes a plurality of bulk acoustic resonators connected between first and second radio frequency (RF) ports to form a frequency band, wherein each of the plurality of bulk acoustic resonators includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes, the plurality of bulk acoustic resonators include first and second bulk acoustic resonators having different differences between a resonant frequency and an antiresonant frequency, and different ratios of a thickness of the piezoelectric layer to a total thickness of the first and second electrodes, and/or different thicknesses of the piezoelectric layer.

A BAW resonator filter can include a BAW resonator pass-band filter ladder, the BAW resonator pass-band filter ladder can be configured to pass frequency components of an input signal in a pass-band of frequencies received at an input node of the BAW resonator pass-band filter ladder to an output node of the BAW resonator pass-band filter ladder. A first rejection-band series resonator can be coupled in series between an input port of the BAW resonator pass-band filter ladder and the input node, the first rejection-band series resonator can have a first anti-resonant frequency peak in a rejection-band of frequencies that is less than the pass-band of frequencies. A second rejection-band series resonator can be coupled in series between an output port of the BAW resonator filter and the output node, the second rejection-band series resonator can have a second anti-resonant frequency peak in the rejection-band of frequencies.