Abstract: Examples of the present invention include unreleased coupled multi-cavity resonators and transmission filters. In some examples, the resonators include resonant cavities coupled by acoustic couplers (ABGCs) and acoustic reflectors (ABRs). These acoustic components enable improved confinement of acoustic modes within the resonator to increase the quality factor (Q) and lower the motional resistance (Rx). A coupled resonator with 5 cavities coupled by 4 ABGCs can achieve a Q of 1095 while a single-cavity resonator of the same device size has a Q of 760. In some examples, the devices can be configured to work as electronic transmission filters in at least two types of filter configurations. In the transmission line filter configuration, the device can include a filter structure in an arrangement (LH)N H (LH)N, defined as a Fabry-Perot Resonator (FPR). In the multi-pole filter configuration, the device can include a filter structure in an arrangement similar to the multi-cavity resonator design.

Abstract: An acoustic resonator includes a wafer and a first phononic crystal disposed on the wafer to define an acoustic waveguide so as to propagate an acoustic wave along a propagation direction. The first phononic crystal includes a first two-dimensional (2D) array of metal stripes having a first period on the propagation direction. The apparatus also includes a second phononic crystal and a third phononic crystal disposed on two sides of the first phononic crystal and having a different period from the first period. The second phononic crystal and the wafer define a first reflector to reflect the acoustic wave. The third phononic crystal and the wafer define a second reflector to reflect the acoustic wave.

Abstract: An acoustic resonator includes a wafer and a first phononic crystal disposed on the wafer to define an acoustic waveguide so as to propagate an acoustic wave along a propagation direction. The first phononic crystal includes a first two-dimensional (2D) array of metal stripes having a first period on the propagation direction. The apparatus also includes a second phononic crystal and a third phononic crystal disposed on two sides of the first phononic crystal and having a different period from the first period. The second phononic crystal and the wafer define a first reflector to reflect the acoustic wave. The third phononic crystal and the wafer define a second reflector to reflect the acoustic wave.

Abstract: A deep trench (DT) MEMS resonator includes a periodic array of unit cells, each of which includes a single DT formed in a semiconductor substrate and filled with a material whose acoustic impedance is different than that of the substrate. The filled DT is used as both an electrical capacitor and a mechanical structure at the same time, making it an elegant design that reduces footprint and fabrication complexity. Adding a second DT to each unit cell in a DT MEMS resonator forms a dual-trench DT (DTDT) MEMS resonator. In a DTDT unit cell, the first DT is filled with a conductor to sense, conduct, and/or generate an acoustic wave. The second DT in the DTDT unit cell is filled with an insulator. The width, filling, etc. of the second DT in the DTDT unit cell can be selected to tune the acoustic passband of the DTDT unit cell.

Abstract: Examples of the present invention include unreleased coupled multi-cavity resonators and transmission filters. In some examples, the resonators include resonant cavities coupled by acoustic couplers (ABGCs) and acoustic reflectors (ABRs). These acoustic components enable improved confinement of acoustic modes within the resonator to increase the quality factor (Q) and lower the motional resistance (Rx). A coupled resonator with 5 cavities coupled by 4 ABGCs can achieve a Q of 1095 while a single-cavity resonator of the same device size has a Q of 760. In some examples, the devices can be configured to work as electronic transmission filters in at least two types of filter configurations. In the transmission line filter configuration, the device can include a filter structure in an arrangement (LH)N H (LH)N, defined as a Fabry-Perot Resonator (FPR). In the multi-pole filter configuration, the device can include a filter structure in an arrangement similar to the multi-cavity resonator design.

Abstract: Example acoustic bandgap devices provided that can be fabricated in a semiconductor fabrication tool based on design check rules. An example device includes a substrate lying in an x-y plane and defining an x-direction and a y-direction, an acoustic resonant cavity over the substrate, and a phononic crystal disposed over the acoustic resonant cavity by generating the phononic crystal as a plurality of unit cells disposed in a periodic arrangement. Each unit cell include: (a) at least one higher acoustic impedance structure having a longitudinal axis oriented in the y-direction and a thickness in the x-direction greater than or about equal to a minimal feature thickness of the semiconductor fabrication tool, and (b) at least one lower acoustic impedance material bordering at least a portion of the at least one higher acoustic impedance structure and forming at least a portion of a remainder of the respective unit cell.

Abstract: Example acoustic bandgap devices provided that can be fabricated in a semiconductor fabrication tool based on design check rules. An example device includes a substrate lying in an x-y plane and defining an x-direction and a y-direction, an acoustic resonant cavity over the substrate, and a phononic crystal disposed over the acoustic resonant cavity by generating the phononic crystal as a plurality of unit cells disposed in a periodic arrangement. Each unit cell include: (a) at least one higher acoustic impedance structure having a longitudinal axis oriented in the y-direction and a thickness in the x-direction greater than or about equal to a minimal feature thickness of the semiconductor fabrication tool, and (b) at least one lower acoustic impedance material bordering at least a portion of the at least one higher acoustic impedance structure and forming at least a portion of a remainder of the respective unit cell.

Abstract: A microelectromechanical (MEM) resonator includes a resonant cavity disposed in a first layer of a first solid material disposed on a substrate and a first plurality of reflectors disposed in the first layer in a first direction with respect to the resonant cavity and to each other. Each of the first plurality of reflectors comprises an outer layer of a second solid material and an inner layer of a third solid material. The inner layer of each of the first plurality of reflectors is adjacent in the first direction to the outer layer of each reflector and to either the outer layer of an adjacent reflector or the resonant cavity.

Abstract: An piezoelectric electromechanical transistor has first and second terminals formed in a semiconductor region, a gate and a piezoelectric region between the gate and the semiconductor region. The piezoelectric region may be configured to drive the semiconductor region to vibrate in response to a signal applied to the gate. The transistor may be configured to produce a signal at the first terminal at least partially based on vibration of the semiconductor region.

Abstract: A resonator body has an inversion gate, an accumulation gate, and a center region. The resonator body also has a source contact coupled to the center region and a drain contact coupled to the center region. The resonator body further has a first dielectric layer coupled between the inversion gate and the center region. The resonator body also has a second dielectric layer coupled between the accumulation gate and the center region. A resonant body transistor is also disclosed. The resonant body transistor has an inversion gate electrode, an accumulation gate electrode, a source electrode, a drain electrode, and a plurality of anchor beams. The resonant body transistor also has a resonator body coupled-to and suspended-from the inversion gate electrode, the accumulation gate electrode, the source electrode, and the drain electrode by the plurality of anchor beams. A resonant body oscillator is also disclosed.

Abstract: An piezoelectric electromechanical transistor has first and second terminals formed in a semiconductor region, a gate and a piezoelectric region between the gate and the semiconductor region. The piezoelectric region may be configured to drive the semiconductor region to vibrate in response to a signal applied to the gate. The transistor may be configured to produce a signal at the first terminal at least partially based on vibration of the semiconductor region.

Abstract: A microelectromechanical (MEM) resonator includes a resonant cavity disposed in a first layer of a first solid material disposed on a substrate and a first plurality of reflectors disposed in the first layer in a first direction with respect to the resonant cavity and to each other. Each of the first plurality of reflectors comprises an outer layer of a second solid material and an inner layer of a third solid material. The inner layer of each of the first plurality of reflectors is adjacent in the first direction to the outer layer of each reflector and to either the outer layer of an adjacent reflector or the resonant cavity.

Abstract: A resonator body has an inversion gate, an accumulation gate, and a center region. The resonator body also has a source contact coupled to the center region and a drain contact coupled to the center region. The resonator body further has a first dielectric layer coupled between the inversion gate and the center region. The resonator body also has a second dielectric layer coupled between the accumulation gate and the center region. A resonant body transistor is also disclosed. The resonant body transistor has an inversion gate electrode, an accumulation gate electrode, a source electrode, a drain electrode, and a plurality of anchor beams. The resonant body transistor also has a resonator body coupled-to and suspended-from the inversion gate electrode, the accumulation gate electrode, the source electrode, and the drain electrode by the plurality of anchor beams. A resonant body oscillator is also disclosed.

Abstract: A MEMS filter has an input layer for receiving a signal input, and an output layer for providing a signal output. The MEMS filter also has a first resonator and a second resonator coupled to the first resonator such that movement transduced in the first resonator by the signal input causes movement of the second resonator which transduces the signal output. A method of manufacturing a MEMS filter is also disclosed. A dielectric layer is formed on a base. A patterned electrode layer is formed at least in part on the dielectric layer. The base is etched to define a resonator structure. A method of adjusting a desired input impedance and an output impedance of a dielectrically transduced MEMS filter having transduction electrodes coupled to a dielectric film is further disclosed. The method includes adjusting a DC bias voltage on the transduction electrodes.

Abstract: A MEMS filter has an input layer for receiving a signal input, and an output layer for providing a signal output. The MEMS filter also has a first resonator and a second resonator coupled to the first resonator such that movement transduced in the first resonator by the signal input causes movement of the second resonator which transduces the signal output. A method of manufacturing a MEMS filter is also disclosed. A dielectric layer is formed on a base. A patterned electrode layer is formed at least in part on the dielectric layer. The base is etched to define a resonator structure. A method of adjusting a desired input impedance and an output impedance of a dielectrically transduced MEMS filter having transduction electrodes coupled to a dielectric film is further disclosed. The method includes adjusting a DC bias voltage on the transduction electrodes.