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.

Methods of forming a shear-mode acoustic wave filter on V-shaped grooves of a [100] crystal orientation Si layer over a substrate and the resulting devices are provided. Embodiments include forming a set of V-shaped grooves in a [100] crystal orientation Si layer over a substrate; and forming a shear-mode acoustic wave filter over the V-shaped grooves, the shear-mode acoustic wave filter including a first metal layer, a thin-film piezoelectric layer, and a second metal layer, wherein the second metal layer is an IDT pattern or a sheet.

A microelectromechanical resonator device is provided having two-dimensional resonant rods. The resonator device has a piezoelectric layer formed with a plurality of alternating rods and trenches. A bottom electrode is in contact with a bottom surface of the piezoelectric layer. A top electrode metal grating of conductive strips is aligned in contact with corresponding rods of the piezoelectric layer.

A crystal oscillator includes an oscillating substrate, a hollow frame, a first electrode, and a second electrode. The oscillating substrate includes a main oscillating region and a thinned region that has a thickness smaller than that of the main oscillating region. The first and second electrodes are disposed on a first surface of the oscillating substrate and a second surface opposite to the first surface, respectively. The hollow frame is disposed on the second surface. The second electrode includes a second electrode portion that has at least one opening in positional correspondence with the thinned region. A method for making the crystal oscillator is also provided herein.

A SAW device manufacturing method includes a piezoelectric ceramic substrate polishing step of polishing a first surface of the piezoelectric ceramic substrate, a support substrate polishing step of polishing a first surface of the support substrate, a bonding step of bonding the first surface of the piezoelectric ceramic substrate to the first surface of the support substrate to thereby form a stacked substrate, a grinding step of grinding a second surface of the piezoelectric ceramic substrate, and a vibration diffusion layer forming step of applying a laser beam to the stacked substrate in the condition where the focal point of the laser beam is positioned inside the piezoelectric ceramic substrate to thereby form a modified layer as a vibration diffusion layer inside the piezoelectric ceramic substrate.

In an array of single crystal acoustic resonators, the effective coupling coefficient of first and second strained single crystal filters are individually tailored in order to achieve desired frequency responses. In a duplexer embodiment, the effective coupling coefficient of a transmit band-pass filter is lower than the effective coupling coefficient of a receive band-pass filter of the same duplexer. The coefficients can be tailored by varying the ratio of the thickness of a piezoelectric layer to the total thickness of electrode layers or by forming a capacitor in parallel with an acoustic resonator within the filter for which the effective coupling coefficient is to be degraded. Further, a strained piezoelectric layer can be formed overlying a nucleation layer characterized by nucleation growth parameters, which can be configured to modulate a strain condition in the strained piezoelectric layer to adjust piezoelectric properties for improved performance in specific applications.

Methods of forming a shear-mode acoustic wave filter on V-shaped grooves of a [100] crystal orientation Si layer over a substrate and the resulting devices are provided. Embodiments include forming a set of V-shaped grooves in a [100] crystal orientation Si layer over a substrate; and forming a shear-mode acoustic wave filter over the V-shaped grooves, the shear-mode acoustic wave filter including a first metal layer, a thin-film piezoelectric layer, and a second metal layer, wherein the second metal layer is an IDT pattern or a sheet.

An acoustic wave device includes a piezoelectric layer, an interdigital transducer, and a slow wave propagation overlay over a portion of the interdigital transducer. By providing electrode fingers of the interdigital transducer such that a portion of the width thereof is dependent on an electrode period, a desirable wave mode may be maintained in the acoustic wave device. Further, by varying a width of the slow wave propagation overlay based on the electrode period, the desirable wave mode may be further maintained.

A SAW device manufacturing method includes a piezoelectric ceramic substrate polishing step of polishing a first surface of the piezoelectric ceramic substrate, a support substrate polishing step of polishing a first surface of the support substrate, a bonding step of bonding the first surface of the piezoelectric ceramic substrate to the first surface of the support substrate to thereby form a stacked substrate, a grinding step of grinding a second surface of the piezoelectric ceramic substrate, and a vibration diffusion layer forming step of applying a laser beam to the stacked substrate in the condition where the focal point of the laser beam is positioned inside the piezoelectric ceramic substrate to thereby form a modified layer as a vibration diffusion layer inside the piezoelectric ceramic substrate.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; lower and upper electrodes facing each other across at least a part of the piezoelectric film; a first insertion layer located between the lower and upper electrodes and located in at least a part of an outer peripheral region within a resonance region in which the lower and upper electrodes face each other across the piezoelectric film, the first insertion layer being not located in a center region of the resonance region; and a second insertion layer located between the lower and upper electrodes and located in at least a part of the outer peripheral region, the second insertion layer being not located in the center region, a position of an edge of the second insertion layer being different from a position of an edge of the first insertion film in the resonance region.