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.

A temperature compensated oscillation circuit includes an oscillation circuit that oscillates a resonator, a fractional N-PLL circuit that multiplies frequency of an oscillation signal which is output by the oscillation circuit, on the basis of a frequency division ratio which is input, a temperature measurement unit that measures temperature, and a storage unit that stores a temperature correction table for correcting frequency temperature characteristics of the oscillation signal, in which the frequency division ratio of the fractional N-PLL circuit is set on the basis of a measurement value obtained by the temperature measurement unit and the temperature correction table.

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 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 filter device includes a first path, a second path, and a capacitor. The first path includes at least one ladder filter circuit and connects a first terminal and a second terminal. The at least one ladder filter circuit includes a parallel arm resonator connected to a ground terminal. The second path includes a grounded resonator and is connected in parallel with any of the at least one ladder filter circuit. One end of the capacitor is connected to the second path, and the other end of the capacitor is connected to a third path which connects the parallel arm resonator and the ground terminal.

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.

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.

A film bulk acoustic wave resonator (FBAR) includes a piezoelectric film disposed in a central region defining a main active domain in which a main acoustic wave is generated during operation, and in recessed frame regions disposed laterally on opposite sides of the central region. The piezoelectric film disposed in the recessed frame regions includes a greater concentration of defects than a concentration of defects in the piezoelectric film disposed in the central region.

A laterally coupled multi-mode monolithic filter includes: a substrate; a piezoelectric film formed on the substrate; a ground electrode formed on a first surface of the piezoelectric film; and signal electrodes formed on a second surface of the piezoelectric film and arranged in parallel to each other, the second surface being opposite to the first surface, each of the signal electrodes including a first electrode finger and a second electrode finger, wherein the first electrode finger and the second electrode finger have different electric potentials; adjacent signal electrodes of the signal electrodes are at a distance from each other, the distance being greater than a pitch of the first electrode finger and the second electrode finger.

Acoustic filters and methods of fabricating acoustic filters are disclosed. A filter includes a single-crystal piezoelectric plate having a front surface and a back surface attached to a substrate, and a plurality of acoustic resonators including a first shunt resonator, a second shunt resonator, and one or more series resonators. Each of the plurality of acoustic resonators includes an interdigital transducer (IDT) formed on the front surface of the piezoelectric plate, interleaved fingers of the IDT disposed on a respective diaphragm formed by a portion of the piezoelectric plate that spans a cavity in the substrate. A frequency setting dielectric layer is formed over the first and second shunt resonators but not over the one or more series resonators. The frequency setting dielectric layer has a thickness t1 on the first shunt resonator and a thickness t2 on the second shunt resonator, where t1 is not equal to t2.