Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi-frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

Embodiments of a tunable bandpass microelectromechanical (MEMS) filter are described. In one embodiment, such a filter includes a pair of arch beam microresonators, and a pair of voltage sources electrically coupled to apply a pair of adjustable voltage biases across respective ones of the pair of arch beam microresonators. The pair of voltage sources offer independent tuning of the bandwidth of the filter. Based on the structure and arrangement of the filter, it can be tunable by 125% or more by adjustment of the adjustable voltage bias. The filter also has a relatively low bandwidth distortion, can exhibit less than 2.5 dB passband ripple, and can exhibit sideband rejection in the range of at least 26 dB.

In one aspect, the disclosure relates to a super high frequency (SHF) or extremely high frequency (EHF) bulk acoustic resonator that includes a nanostructure, wherein the nanostructure includes a substrate, a three-dimensional structure disposed on the substrate, wherein the three-dimensional structure includes a planar structure including at least one nanocomponent and a matrix material contacting the nanocomponent on at least one side, the matrix material including an SiGe alloy or Ge. The disclosed bulk acoustic resonator operates at frequencies of from about 100 MHz to about 100 GHz, is capable of self-amplification upon application of direct current or voltage, and has a Q factor amplification exceeding 1. Also disclosed are methods for amplification of mechanical resonance in the disclosed bulk acoustic resonators and devices incorporating the bulk acoustic resonators.

Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi-frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.

Embodiments of a tunable bandpass microelectromechanical (MEMS) filter are described. In one embodiment, such a filter includes a pair of arch beam microresonators, and a pair of voltage sources electrically coupled to apply a pair of adjustable voltage biases across respective ones of the pair of arch beam microresonators. The pair of voltage sources offer independent tuning of the bandwidth of the filter. Based on the structure and arrangement of the filter, it can be tunable by 125% or more by adjustment of the adjustable voltage bias. The filter also has a relatively low bandwidth distortion, can exhibit less than 2.5 dB passband ripple, and can exhibit sideband rejection in the range of at least 26 dB.

An electrical circuit assembly can include a semiconductor integrated circuit, such as fabricated including CMOS devices. A first lateral-mode resonator can be fabricated upon a surface of the semiconductor integrated circuit, such as including a deposited acoustic energy storage layer including a semiconductor material, a deposited piezoelectric layer acoustically coupled to the deposited acoustic energy storage layer, and a first conductive region electrically coupled to the deposited piezoelectric layer and electrically coupled to the semiconductor integrated circuit. The semiconductor integrated circuit can include one or more transistor structures, such as fabricated prior to fabrication of the lateral-mode resonator. Fabrication of the lateral-mode resonator can include low-temperature processing specified to avoid disrupting operational characteristics of the transistor structures.

A piezoelectrically transduced resonator device includes a wafer having a substrate, a buried oxide layer formed on the substrate, and a device layer formed on the buried oxide layer, and a resonator suspended within an air gap of the wafer above the substrate, the resonator including a portion of the device layer, a piezoelectric layer, and top and bottom electrodes contacting top and bottom sides of the piezoelectric layer, wherein the portion of the device layer is not directly connected to the wafer and wherein the resonator is configured to move relative to the substrate under electrostatic force to tune the frequency of the resonator device when a direct current voltage is applied between the substrate and the portion of the device layer of the resonator.

A micromechanical resonator is disclosed. The resonator includes a resonant micromechanical element. A film of annealable material deposited on a facial surface of the element. In one instance, the resonance of the element can be adjusting by using a feedback loop to control annealing of the deposited film.

An electrical circuit assembly can include a semiconductor integrated circuit, such as fabricated including CMOS devices. A first lateral-mode resonator can be fabricated upon a surface of the semiconductor integrated circuit, such as including a deposited acoustic energy storage layer including a semiconductor material, a deposited piezoelectric layer acoustically coupled to the deposited acoustic energy storage layer, and a first conductive region electrically coupled to the deposited piezoelectric layer and electrically coupled to the semiconductor integrated circuit. The semiconductor integrated circuit can include one or more transistor structures, such as fabricated prior to fabrication of the lateral-mode resonator. Fabrication of the lateral-mode resonator can include low-temperature processing specified to avoid disrupting operational characteristics of the transistor structures.

A tunable Q resonator using a capacitive-piezoelectric transducer provides a flexible top electrode above an AlN resonator. The top electrode can be pulled electrostatically towards the resonator and substrate, forming a frictional contact with either the resonator or the combined resonator-electrode structure to the substrate, allowing for electrical tuning the Q of the resonator. With a sufficient electrostatic bias voltage V.sub.b, the resonator may be completely turned OFF, allowing for an integrated switchable AlN resonator. Such switchable resonator may be integrated into a radio frequency (RF) front end as a digitally selectable band pass filter element, obviating the need for ancillary micromechanical switches in the signal path. The device has been demonstrated with a Q approaching 9,000, together with ON/OFF switchability and electromechanical coupling up to 0.63%. Flexible positioning of the top electrode allows for actively controlling the series resonant frequency of the resonator through changes in capacitive coupling.