An electronic package includes a die mounted on a first substrate; a second substrate disposed over the first substrate; a pillar wall extending between a surface of the die and an opposing surface of the second substrate to provide separation between the die and the second substrate, the pillar wall extending about a perimeter bounding the die and enclosing a cavity between the first and second substrates; and an encapsulating layer disposed over the first and second substrates and around the pillar wall. Substantially none of the encapsulating layer ingresses into the cavity.

In an embodiment, a tunable stiffness mechanical filter is provided including an input coupler to a negative stiffness structure with a negative stiffness characteristic, and further including a tuner for tuning the negative stiffness structure. An output sensor is located along the negative stiffness structure. The filter may include an amplifier and/or a driver coupled between the output sensor and the negative stiffness structure.

A microelectromechanical system (MEMS) resonator includes a substrate having a substantially planar surface and a resonant member having sidewalls disposed in a nominally perpendicular orientation with respect to the planar surface. Impurity dopant is introduced via the sidewalls of the resonant member such that a non-uniform dopant concentration profile is established along axis extending between the sidewalls parallel to the substrate surface and exhibits a relative minimum concentration in a middle region of the axis.

A resonator that includes a piezoelectric vibrator, a frame, and a first node generator between the piezoelectric vibrator and the frame. Moreover, a first connecting arm connects the first node generator to the piezoelectric vibrator that opposes the first, and a first holding arm connects the first node generator to a part of the frame that opposes the first node generator. The first node generator includes a width extending in a second direction, which is orthogonal to a first direction of the first connecting arm, that is a maximum width where the first node generator is closer to the first connecting arm than a center of the first node generator relative to the first direction. Moreover, the width of the first node generator gradually decreases from the maximum width as the first node generator extends towards the first holding arm.

A compensation circuit reduces the negative effects of antenna-to-antenna coupling between proximately located antennas. The compensation circuit is coupled between first and second antenna ports. A first transmit/receive path extends from radio frequency (RF) circuitry to the first antenna port. A second transmit/receive path extends from the RF circuitry to the second antenna port. Antennas are coupled to each of the antenna ports. The compensation circuit includes negatively coupled first and second inductors, which are coupled in series between the first antenna port and the second antenna port. At least one shunt acoustic resonator is coupled between a fixed voltage node and a common node between the first and second inductors. In operation, the compensation circuit presents a negative capacitance between the first antenna port and the second antenna port over the first frequency range to reduce the effects of the antenna-antenna coupling.

A high-temperature drive component for a double-ended tuning fork (DETF). The drive component attaches to a surface of at least one of the tines. The drive component includes at least one piezoelectric trace sandwiched at least partially between two electrical traces. At least one of the tines includes a doped silicon base with drive component located thereon. One of the electrical traces is electrically connected to the doped silicon base and the other is electrically isolated from the doped silicon base.

Methods are described for constructing a mechanical resonating structure by applying an active layer on a surface of a compensating structure. The compensating structure comprises one or more materials having an adaptive resistance to deform that reduces a variance in a resonating frequency of the mechanical resonating structure, wherein at least the active layer and the compensating structure form a mechanical resonating structure having a plurality of layers of materials A thickness of each of the plurality of layers of materials results in a plurality of thickness ratios therebetween.

A vibration gyroscope includes: a mass part supported to be displaceable in a first direction and a second direction; an exciter vibrating the mass part in the first direction; and a detector detecting a displacement amount of the mass part in the second direction. The first direction and the second direction are orthogonal to each other. A resonance frequency of the mass part in the first direction coincides with a resonance frequency of the mass part in the second direction. A Q-factor of vibration of the mass part in the second direction is smaller than a Q-factor of vibration of the mass part in the first direction.

A vibration gyroscope includes: a mass part supported to be displaceable in a first direction and a second direction; an exciter vibrating the mass part in the first direction; and a detector detecting a displacement amount of the mass part in the second direction. The first direction and the second direction are orthogonal to each other. A resonance frequency of the mass part in the first direction coincides with a resonance frequency of the mass part in the second direction. A Q-factor of vibration of the mass part in the second direction is smaller than a Q-factor of vibration of the mass part in the first direction.

A resonance device is provided that includes a lower cover; an upper cover coupled to the lower cover; and a resonator that has vibration arms that generate bending vibration in an interior space provided between the lower cover and the upper cover. Moreover, the vibration arms have distal ends provided with metal films on a side that faces the upper cover, and a gap is provided between the distal ends of the vibration arms and the upper cover that is larger than a gap between the distal ends of the vibration arms and the lower cover.