Patent classifications
H03H2009/02456
Characterization and driving method based on the second harmonic, which is enhancing the quality factor and reducing the feedthrough current in varying gap electrostatic MEMS resonators
A method of an open loop characterization of an electrostatic MEMS based resonator with a varying gap, the method including: converting, via a trans-impedance amplifier circuit, an output current signal of the resonator into a voltage; multiplying the output current signal converted into the voltage, by means of a multiplier circuit, with an AC signal or with a different signal at a frequency of the resonator and carrying a second harmonic signal to a main tone; and measuring a frequency response of a signal cleared of frequencies apart from the main tone using a network analyzer.
RESONANCE DEVICE
A resonator that includes a substrate, an insulating film that is formed on the substrate, and vibration regions each of which is formed on the insulating film and includes lower electrodes that are formed on the insulating film, a piezoelectric film that is formed on the lower electrodes, and an upper electrode that is formed on the piezoelectric film. At least one lower electrode of the lower electrodes that are formed on the insulating film has an electric potential that differs from an electric potential of another lower electrode such that at least one vibration region vibrates in antiphase with another vibration region. Moreover, a package seals a resonator and includes the substrate, the insulating film, and the vibration regions and includes a ground terminal for grounding the substrate.
Resonance device
A resonance device is provided that includes a resonator including upper electrodes, a lower electrode, and a piezoelectric thin film formed therebetween. An upper cover is provided with a first surface facing the upper electrodes of the resonator. A power supply terminal is provided on a second surface of the upper cover with the power supply terminal electrically connected to the upper electrodes. Another power supply terminal is on the second surface of the upper cover and is electrically connected to the upper electrodes. A ground terminal is provided on the second surface of the upper cover and is electrically connected to the lower electrode. An area of each power supply terminal are different from one other such that a capacitance formed between the first power supply terminal and the ground terminal is approximately equal to a capacitance formed between the second power supply terminal and the ground terminal.
Resonator electrode shields
A microelectromechanical system (MEMS) resonator includes a resonant semiconductor structure, drive electrode, sense electrode and electrically conductive shielding structure. The first drive electrode generates a time-varying electrostatic force that causes the resonant semiconductor structure to resonate mechanically, and the first sense electrode generates a timing signal in response to the mechanical resonance of the resonant semiconductor structure. The electrically conductive shielding structure is disposed between the first drive electrode and the first sense electrode to shield the first sense electrode from electric field lines emanating from the first drive electrode.
CHARACTERIZATION AND DRIVING METHOD BASED ON THE SECOND HARMONIC, WHICH IS ENHANCING THE QUALITY FACTOR AND REDUCING THE FEEDTHROUGH CURRENT IN VARYING GAP ELECTROSTATIC MEMS RESONATORS
A method of an open loop characterization of an electrostatic MEMS based resonator with a varying gap, the method including: converting, via a trans-impedance amplifier circuit, an output current signal of the resonator into a voltage; multiplying the output current signal converted into the voltage, by means of a multiplier circuit, with an AC signal or with a different signal at a frequency of the resonator and carrying a second harmonic signal to a main tone; and measuring a frequency response of a signal cleared of frequencies apart from the main tone using a network analyzer.
MICROELECTROMECHANICAL SYSTEM RESONATOR DEVICES AND OSCILLATOR CONTROL CIRCUITS
Reference oscillators are ubiquitous in timing applications generally, and in modern wireless communication devices particularly. Microelectromechanical system (MEMS) resonators are of particular interest due to their small size and potential for integration with other MEMS devices and electrical circuits on the same chip. In order to support their use in high volume low cost applications it would be beneficial for MEMS designers to have MEMS resonator designs and manufacturing processes that whilst employing low cost low resolution semiconductor processing yield improved resonator performance thereby reducing the requirements of the oscillator circuitry. It would be further beneficial for the oscillator circuitry to be able to leverage the improved noise performance of differential TIAs without sacrificing power consumption.
Differential split-electrode feedthrough cancellation mechanism
An electromechanical resonator including a drive electrode set having at least one pair of alternating pole interdigitated drive electrodes and including a sense electrode set having at least one pair of alternating pole interdigitated sense electrodes.
Resonator electrode shields
A microelectromechanical system (MEMS) resonator includes a resonant semiconductor structure, drive electrode, sense electrode and electrically conductive shielding structure. The first drive electrode generates a time-varying electrostatic force that causes the resonant semiconductor structure to resonate mechanically, and the first sense electrode generates a timing signal in response to the mechanical resonance of the resonant semiconductor structure. The electrically conductive shielding structure is disposed between the first drive electrode and the first sense electrode to shield the first sense electrode from electric field lines emanating from the first drive electrode.
Resonator electrode shields
A microelectromechanical system (MEMS) resonator includes a resonant semiconductor structure, drive electrode, sense electrode and electrically conductive shielding structure. The first drive electrode generates a time-varying electrostatic force that causes the resonant semiconductor structure to resonate mechanically, and the first sense electrode generates a timing signal in response to the mechanical resonance of the resonant semiconductor structure. The electrically conductive shielding structure is disposed between the first drive electrode and the first sense electrode to shield the first sense electrode from electric field lines emanating from the first drive electrode.
Resonator electrode shields
A microelectromechanical system (MEMS) resonator includes a resonant semiconductor structure, drive electrode, sense electrode and electrically conductive shielding structure. The first drive electrode generates a time-varying electrostatic force that causes the resonant semiconductor structure to resonate mechanically, and the first sense electrode generates a timing signal in response to the mechanical resonance of the resonant semiconductor structure. The electrically conductive shielding structure is disposed between the first drive electrode and the first sense electrode to shield the first sense electrode from electric field lines emanating from the first drive electrode.