A first filter of a multiplexer has a ladder filter structure defined by acoustic wave resonators. An imaginary line obtained by connecting second ends of electrode fingers included in one comb-shaped electrode among a pair of comb-shaped electrodes of each resonator intersects a reference line that is a straight line extending in an acoustic wave propagation direction. When an angle defined by the reference line and the imaginary line of a first series resonator is represented by a first slant angle, an angle defined by the reference line and the imaginary line of a parallel resonator is represented by a second slant angle, and an angle defined by the reference line and the imaginary line of acoustic wave resonators is represented by a third slant angle, at least one of the first slant angle and the second slant angle is smaller than the third slant angle.

A micro-electro-mechanical-system (MEMS) device comprises an inertial component configured for being connected to a structure by a flexible connection allowing the inertial component to deform or move relative to the structure in response to an external stimulus applied to the structure. One or more resonant components are connected to the structure or inertial component, the resonant component(s) having resonant mode(s). Transduction unit(s) measures an oscillatory motion of the resonant component relative to the inertial component and/or structure. An electronic control unit applies a pump of electrostatic force to induce an oscillatory motion of the resonant component(s) in the resonant mode, the oscillatory motion being a non-linear function of a strength of the electrostatic force. The resonant component is configured to be coupled to the inertial component and/or the structure such that a deformation and/or motion of the inertial component in response to an external stimulus changes the strength of the pump, the electronic control unit configured for producing and outputting an output signal being a mathematical function of the measured oscillatory motion. A system for producing a neuromorphic output for a MEMS device exposed to external stimuli is also provided.

A first filter of a multiplexer has a ladder filter structure including a plurality of series resonators and a plurality of parallel resonators. Each resonator is an acoustic wave resonator that includes an IDT electrode including a pair of comb-shaped electrodes. A portion having a unit area, in a plan view of a substrate on which the resonators are provided, has a larger weight in at least one of the IDT electrode of the series resonator that is closest to the common terminal, among the series resonator, and the IDT electrode of the parallel resonator that is closest to the common terminal than in the IDT electrode of each of the remainder of the plurality of acoustic wave resonators.

There is provided a SAW filter manufacturing method for manufacturing a SAW filter from a piezoelectric substrate having planned dividing lines set on a top surface of the piezoelectric substrate, and having a device including comb-shaped electrodes in regions demarcated by the planned dividing lines. The method includes a structure forming step of forming a structure having projections and depressions on an undersurface side of the piezoelectric substrate by irradiating the piezoelectric substrate with a laser beam of a wavelength absorbable by the piezoelectric substrate from the undersurface side of the piezoelectric substrate, and a dividing step of dividing the piezoelectric substrate along the planned dividing lines after the structure forming step.

An acoustic resonator includes a piezoelectric stack including a piezoelectric layer having a top surface and a bottom surface, a top electrode layer disposed above the top surface, and a bottom electrode layer disposed below the bottom surface. A number of acoustic wave reflectors are disposed on a side of the bottom electrode layer opposite the piezoelectric layer. Each acoustic wave reflector includes a high acoustic impedance layer and may include a low acoustic impedance layer. The acoustic resonator may include a tether that extends laterally to a stacking direction of the layers of the piezoelectric stack. A supporting structure may be coupled to the tether opposite the acoustic resonator for anchoring the acoustic resonator. A mirror, one or more phononic crystals, or both may be positioned on proximate the tether opposite the acoustic resonator to avoid resonant waves from exiting the acoustic resonator in use.

A resonator with stabilized resonant frequency that includes a lower electrode, a plurality of upper electrodes, and a piezoelectric film disposed between the lower electrode and the plurality of upper electrodes. Moreover, an upper lid having a first and second opposing surfaces is provided so that the first surface faces and seals a first surface of the resonator. In addition, a lower lid having a first and second opposing surfaces is provided so that the first surface faces and seals a second surface of the resonator. The resonator further includes a power terminal electrically connected to the upper electrodes and a ground terminal provided on the second surface of the upper lid. The lower electrode is electrically connected to the ground terminal by the upper lid.

The disclosure describes techniques to adjust the geometry of a pendulous proof mass VBA to operate with sufficient signal-to-noise performance while avoiding nonlinear mechanical coupling at specified frequencies. The techniques of this disclosure include adding anchor support flexures to a resonator connection structure, adjusting shape, thickness, and the material of VBA components and of the VBA support structure to both control the frequency of any mechanical resonant modes and to adjust the mechanical mode frequencies away from desired operating frequencies and, in some examples, away from harmonics of desired operating frequencies.

This disclosure describes techniques of configuring capacitive comb fingers of an accelerometer resonator into discreet electrodes with drive electrodes and at least two sense electrodes. The routing of electrical signals is configured to produce parasitic feedthrough capacitances that are approximately equal. The sense electrodes may be placed on opposite sides of the moving resonator beams such that the changes in capacitance with respect to displacement (e.g. dC/dx) are approximately equal in magnitude and opposite in sign. The arrangement may result in sense currents that are also opposite in sign and result in feedthrough currents of the same sign. The sense outputs from the resonators may be connected to a differential amplifier, such that the difference in output currents may mitigate the effect of the feedthrough currents and cancel parasitic feedthrough capacitance. Parasitic feedthrough capacitance may cause increased accelerometer noise and reduced bias stability.

The disclosure describes techniques to damp the proof mass motion of an accelerometer while achieving an underdamped resonator. In an example of an in-plane micro-electromechanical systems (MEMS) VBA, the proof mass may contain one or more damping combs that include one or more banks of rotor comb fingers attached to the proof mass. The rotor comb fingers may be interdigitated with stator comb fingers that are attached to fixed geometry. These damping comb fingers may provide air damping for the proof mass when the MEMS die is placed into a package containing a pressure above a vacuum. The geometry of the damping combs with a reduced air gap and large overlap area between the rotor comb fingers and stator comb fingers. The geometry of resonator of the VBA of this disclosure may be configured to avoid air damping.

A resonator device may include a stacked first resonator and second resonator. The first resonator may be configured to resonate at a first operating frequency, and the second resonator may be configured to resonate at a second operating frequency different from the first operating frequency. The first resonator may include a first electrode and a first active layer arranged over the first electrode. The second resonator may include a second active layer arranged over the first active layer, and a second electrode arranged over the second active layer. The stacked first resonator and second resonator may be coupled to a reconfiguration switch for selectively operating at the first operating frequency or the second operating frequency. One of the first resonator and the second resonator is active upon selection by the reconfiguration switch, while the other resonator is inactive.