Abstract: A BAW resonator includes first and second electrodes located over a substrate. A piezoelectric layer is located between the first and second electrodes. A guard ring is located between the piezoelectric layer and the second electrode, and is spaced apart from a perimeter of the electrode. The guard ring has a width in a range from 2.5 ?m to 3.5 ?m.

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: A circuit includes: integrated circuit (IC) layers; a cavity formed in at least one of the IC layers; and a micro-acoustic resonator suspended in the cavity by an anchor. The anchor includes: a bridge portion coupled to the micro-acoustic resonator and extending over the cavity; a first acoustic reflector portion adjacent the bridge portion, extending over the cavity, and oriented differently than the bridge portion; and a second acoustic reflector portion adjacent the first acoustic reflector portion, extending over the cavity, and oriented differently than the first acoustic reflector portion.

Abstract: In one example, a method of forming a bulk acoustic wave (BAW) resonator comprises: forming an electrode on at least one of a semiconductor substrate, a sacrificial layer, or an acoustic reflector; and forming a piezoelectric layer on the electrode, the piezoelectric layer having a convex surface.

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: In bulk acoustic wave (BAW) resonators having convex surfaces, an example BAW resonator includes a first electrode, a piezoelectric layer formed on the first electrode, the piezoelectric layer having a convex surface, and a second electrode formed on the convex surface. An example integrated circuit (IC) package includes a BAW resonator in the IC package, the BAW resonator including a piezoelectric layer having a convex surface.

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: In some examples, a device includes a substrate, an oxide layer, and a resonator structure. The substrate is configured in a released-resonator architecture. The substrate has a first surface that is a roughened first surface and a second surface opposite to the first surface. The second surface exposed to a cavity of the released-resonator architecture.

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: 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: An encapsulation chip manufacturing method includes forming first and second dicing grooves in a surface of a cap wafer and aligning the cap wafer and a device substrate such that the surface of the cap wafer faces a surface of the device substrate. The device substrate includes a device affixed to the surface and a bond pad on the surface and coupled to the device. The cap wafer is bonded to the device substrate and partially diced at the first and second dicing grooves such that the bond pad is exposed. Aligning the cap wafer and the device substrate includes aligning the first and second dicing grooves between the bond pad and a bonding area at which the cap wafer is bonded to the device substrate. A width of the first and second dicing grooves prevents cap wafer dust formed during the partial dicing from falling on the bond pad.

Abstract: A temperature compensated oscillator circuit includes a first oscillator, a second oscillator, a first divider, a second divider, a frequency ratio circuit, and a temperature compensation circuit. The first divider is coupled to the first oscillator, and is configured to divide a frequency of a first oscillator signal generated by the first oscillator. The second divider is coupled to the second oscillator, and is configured to divide a frequency of a second oscillator signal generated by the second oscillator. The frequency ratio circuit is coupled to the first divider and the second divider, and is configured to determine a frequency ratio of an output of the first divider to an output of the second divider. The temperature compensation circuit is coupled to the frequency ratio circuit and the first oscillator, and is configured to generate a compensated frequency based on the frequency ratio and the first oscillator signal.

Abstract: A temperature compensated oscillator circuit includes a first oscillator, a second oscillator, a first divider, a second divider, a frequency ratio circuit, and a temperature compensation circuit. The first divider is coupled to the first oscillator, and is configured to divide a frequency of a first oscillator signal generated by the first oscillator. The second divider is coupled to the second oscillator, and is configured to divide a frequency of a second oscillator signal generated by the second oscillator. The frequency ratio circuit is coupled to the first divider and the second divider, and is configured to determine a frequency ratio of an output of the first divider to an output of the second divider. The temperature compensation circuit is coupled to the frequency ratio circuit and the first oscillator, and is configured to generate a compensated frequency based on the frequency ratio and the first oscillator signal.

Abstract: A circuit includes a semiconductor substrate and an integrated passive device. The integrated passive device is on a surface of the semiconductor substrate. The integrated passive device is in a metal layer on the semiconductor substrate. The metal layer is at least tens of micrometers thick. The integrated passive device may be an inductor or a capacitor in some examples.

Abstract: In a described example, an apparatus includes: a first semiconductor die with a component on a first surface; a second semiconductor die mounted on a package substrate and having a third surface facing away from the package substrate; a solder seal bonded to and extending from the first surface of the first semiconductor die flip chip mounted to the third surface of the second semiconductor die, the solder seal at least partially surrounding the stress sensitive component; a first solder joint formed between the solder seal and the third surface of the second semiconductor die; a second solder joint formed between solder at an end of the post connect and the third surface of the second semiconductor die; and a mold compound covering the second surface of the first semiconductor die, a portion of the second semiconductor die, and an outside periphery of the solder seal.

Abstract: An integrated circuit (IC) resonator module for an IC package includes an acoustic resonator having a surface and a Bragg reflector adhered to the surface of the acoustic resonator. The Bragg reflector includes low impedance layers formed of a first material with a first acoustic impedance and a high impedance layer formed of a second material with a second acoustic impedance. The second acoustic impedance is greater than the first acoustic impedance. The Bragg reflector further includes a Bragg grating layer formed of randomly or periodically spaced patches of the second material separated by vias filled with the first material.

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: An example integrated circuit package includes an acoustic wave resonator, the acoustic wave resonator including a Fresnel surface. In some examples, the Fresnel surface includes a plurality of recessed features and/or protruding features at different locations on the Fresnel surface, each of the plurality of features to confine main mode acoustic energy from a respective portion of the Fresnel surface in a central portion of the acoustic wave resonator.