Abstract: A circuit includes: a first resonator; a temperature compensation circuit including a resonator group-delay analyzer and a second resonator; oscillator control circuitry; and a controller. The resonator group-delay analyzer is configured to determine a group-delay parameter responsive to operations of the second resonator. The controller is configured to provide a control signal responsive to the group-delay parameter. The oscillator control circuitry is configured to adjust a frequency of an output signal of the oscillator control circuitry responsive to the control signal.

Abstract: An example apparatus includes: a semiconductor substrate; a mechanical resonator supported by the substrate, the mechanical resonator including an array of capacitors; and a plasmonic infrared (IR) absorber including an array of metal structures. The mechanical resonator is between the substrate and the IR absorber.

Abstract: A micro-mechanical resonator die includes: micro-mechanical resonator die layers; a cavity formed in at least one of the micro-mechanical resonator die layers; and a micro-mechanical resonator suspended in the cavity. The micro-mechanical resonator includes: a base; a first resonator portion extending from the base along a first plane; and a second resonator portion extending from the base along a second plane. The first resonator portion is configured to operate in an out-of-plane flexural mode that displaces at least part of the first resonator portion out of the first plane. The second resonator portion is configured to operate in an out-of-plane flexural mode that displaces at least part of the second resonator portion out of the second plane and out-of-phase relative to the first resonator portion.

Abstract: In some examples, an apparatus includes a first metal layer having a thickness, a piezoelectric material layer having a first side and a second side that is opposite the first side, the piezoelectric material layer first side abutting the first metal layer, the piezoelectric material layer second side having recesses, and a second metal layer abutting the piezoelectric material layer second side, the second metal layer having extensions that fill the recesses to form a metal frame that is at least partially recessed into the piezoelectric material layer. The first metal layer, the piezoelectric material layer, and the second metal layer form a resonator body. The metal frame has a shape governing a resonant mode of the resonator body.

Abstract: A laterally vibrating bulk acoustic wave (LVBAW) resonator includes a piezoelectric plate sandwiched between first and second metal layers. The second metal layer is patterned into an interdigital transducer (IDT) with comb-shaped electrodes having interlocking fingers. The width and pitch of the fingers of the electrodes determine the resonant frequency. A combined thickness of the first and second metal layers and the piezoelectric layer is less than the pitch of the interlocking fingers.

Abstract: A tunable bulk acoustic wave (BAW) resonator includes: a first electrode adapted to be coupled to an oscillator circuit; a second electrode adapted to be coupled to the oscillator circuit; and a piezoelectric layer between the first electrode and the second electrode; and a Bragg mirror. The Bragg mirror has: a metal layer; and a dielectric layer between the metal layer and either of the first electrode or the second electrode. The tunable BAW resonator also includes: a radio-frequency (RF) signal source having a first end and a second end, the first end coupled to the first electrode, and the second end coupled to the second electrode; and an amplifier circuit between either the first electrode or the second electrode and the Bragg mirror metal layer.

Abstract: A laterally vibrating bulk acoustic wave (LVBAW) resonator includes a piezoelectric plate sandwiched between first and second metal layers. The second metal layer is patterned into an interdigital transducer (IDT) with comb-shaped electrodes having interlocking fingers. The width and pitch of the fingers of the electrodes determine the resonant frequency. A combined thickness of the first and second metal layers and the piezoelectric layer is less than the pitch of the interlocking fingers.

Abstract: An optical detector system includes a light source configured to emit light having a frequency spectrum and modulated in time, and an optical detector configured to detect an intensity of the light at a wavelength range within the frequency spectrum. The optical detector includes a piezoelectric layer, a first metal layer coupled to a first surface of the piezoelectric layer, a second metal layer coupled to a second surface of the piezoelectric layer, and a plasmonic metasurface coupled to the first metal layer and configured to absorb the light at the wavelength range, the plasmonic metasurface including metal structures and a dielectric layer disposed on the first metal layer. The optical detector system further includes a voltage detector coupled to the first metal layer and the second metal layer, the voltage detector configured to detect a voltage at a frequency of the modulated light.

Abstract: A piezoelectric resonator includes a first conductive layer, and a piezoelectric layer affixed to a first side of the first conductive layer. The piezoelectric resonator also includes a stair step frame structure affixed to a first side of the piezoelectric layer, and a second conductive layer, affixed to the first side of the piezoelectric layer and covering the stair step frame structure.

Abstract: A torque sensor chip including a semiconductor substrate, an acoustic reflector formed on the semiconductor substrate, and first and second Lamb wave resonators (LWRs). The first LWR is formed on a side of the acoustic reflector opposite the semiconductor substrate. The first LWR is at a first angle with respect to an axis of the IC. The second LWR also is formed on the side of the acoustic reflector opposite the semiconductor substrate. The second LWR is at a second angle, different than the first angle, with respect to the axis of the IC.

Abstract: An example apparatus includes: a semiconductor substrate; a mechanical resonator supported by the substrate, the mechanical resonator including an array of capacitors; and a plasmonic infrared (IR) absorber including an array of metal structures. The mechanical resonator is between the substrate and the IR absorber.

Abstract: An apparatus for an optical detector includes a bulk acoustic wave (BAW) resonator including a piezoelectric layer and a metal layer, an acoustic Bragg mirror on the BAW resonator and including a first acoustic impedance layer and a second acoustic impedance layer different than the first acoustic impedance layer, and a plasmonic metasurface on the acoustic Bragg mirror and including structures of geometric patterns arranged in an array.

Abstract: A resonator includes a substrate, an acoustic Bragg mirror disposed above the substrate, and a bottom metal layer disposed above the acoustic Bragg mirror. The resonator also includes a piezoelectric plate disposed above the bottom metal layer. The resonator further includes a top metal layer disposed above the piezoelectric plate. The top metal layer comprises multiple fingers within a single plane and the width of each of the fingers is between 75%-125% of a thickness of the piezoelectric plate.

Abstract: A semiconductor system includes a substrate. The substrate has a front side and a back side. A device is formed on the front side of the substrate. A vertical spring is etched in the substrate about the device. A trench is etched in the front side of the substrate about the device. A wall of the trench forms a side of the vertical spring.

Abstract: An example semiconductor package includes a semiconductor die configured to detect a force. In addition, the semiconductor package includes a mold compound covering the semiconductor die. Further, the semiconductor package includes an engagement surface including a pattern of projections adapted to engage with a mounting surface on a member of interest.

Abstract: A MEMS resonator is operated at its parallel resonance frequency. An acoustic wave is propagated laterally away from a central region of the MEMS resonator through a piezoelectric layer of the MEMS resonator. The propagating acoustic wave is attenuated with concentric confiners that surround and are spaced apart from a perimeter of an electrode that forms the MEMS resonator.

Abstract: A micromechanical system (MEMS) resonator includes a base substrate. A piezoelectric layer has a first electrode attached to a first surface of the piezoelectric layer and a second electrode attached to a second surface of the piezoelectric layer opposite the first electrode. The first electrode is bounded by a perimeter edge. A patterned acoustic mirror is formed on a top surface of the first electrode opposite the piezoelectric layer, such that the patterned acoustic mirror covers a border strip of the top surface of the first electrode at the perimeter edge and does not cover an active portion of the top surface of the first electrode.

Abstract: A differential nondispersive infrared (NDIR) sensor incorporates an infrared (IR) chopper and multiple multi-bit digital registers to store and compare parameter ratio values, as may be digitally calibrated to corresponding temperature values, from chopper clock cycle portions in which a plasmonic MEMS detector is irradiated by the IR chopper with such values from chopper clock cycle portions in which the IR detector is not irradiated by the IR chopper. The plasmonic MEMS detector is referenced to a reference MEMS device via a parameter-ratio engine. The reference device can include a broadband IR reflector or can have a lower-absorption metasurface pattern giving it a lower quality factor than the plasmonic detector. The resultant enhancements to accuracy and precision of the NDIR sensor enable it to be used as a sub-parts-per-million gas concentration sensor or gas detector having laboratory, commercial, in-home, and battlefield applications.

Abstract: A device includes a substrate having first and second layers and an insulator layer between the first and second layers. A microelectromechanical system (MEMS) structure is provide on a portion of the second layer. A trench is formed in the second layer and around at least a part of a periphery of the portion of the second layer. An undercut is formed in the insulator layer and adjacent to the portion of the second layer. The undercut separates the portion of the second layer from the first layer. First and second pinholes extend from a plane of the insulator layer and in the first layer. The first and second pinholes are in fluid communication with the undercut and the trench.

Abstract: A micromechanical system (MEMS) resonator includes a base substrate. A piezoelectric layer has a first electrode attached to a first surface of the piezoelectric layer and a second electrode attached to a second surface of the piezoelectric layer opposite the first electrode. The first electrode is bounded by a perimeter edge. A patterned acoustic mirror is formed on a top surface of the first electrode opposite the piezoelectric layer, such that the patterned acoustic mirror covers a border strip of the top surface of the first electrode at the perimeter edge and does not cover an active portion of the top surface of the first electrode.