Roozbeh Tabrizian

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This paper reports on a new implementation of integrated lumped filters with improved out-of-band rejection and pass-band loss. Inductive parasitics are exploited to provide additional transmission zeros at the high frequency end, which can improve both the out-of-band rejection and roll-off. Thick silver is electroplated to reduce the insertion loss and(More)
—Fundamental characteristics of MEMS resonators such as acoustic velocity and energy dissipation may have strong temperature and process dependencies that must be carefully compensated in applications requiring high degrees of stability and accuracy. This paper presents an overview of compensation, tuning, and trimming techniques for MEMS resonators. The(More)
This paper reports on the design, implementation and characterization of a low phase-noise 27 MHz MEMS oscillator with sub-ppm temperature instability based on a high-Q composite bulk acoustic wave (BAW) resonator. An array of silicon dioxide (SiO 2) pillars has been uniformly embedded in the body of a piezoelectrically transduced silicon resonator to(More)
— This paper presents a passive temperature compensation technique that can provide full cancellation of the linear temperature coefficient of frequency (TCF 1) in silicon resonators. A uniformly distributed matrix of silicon dioxide pillars is embedded inside the silicon substrate to form a homogenous composite silicon oxide platform (SilOx) with nearly(More)
—This paper reports on the design, simulation and characterization of small form factor, tunable piezoelectric MEMS resonators for real time clock applications (32.768 kHz). The structures were fabricated on a thin-film AlN-on-SOI substrate to enable piezoelectric actuation of an out-of-plane flexural mode, as well as electrostatic frequency tuning by(More)
This paper reports on the design, fabrication, and characterization of a small form factor, piezoelectrically transduced, tunable micromechanical resonator for real-time clock (RTC) applications (32.768 kHz). The device was designed to resonate in an out-of-plane flexural mode to simultaneously achieve low-frequency operation and reduced motional resistance(More)
—This paper presents tunable width-extensional mode bulk acoustic resonators that are piezoelectrically-actuated and sensed using thin layers of AlN on the sidewalls as well as the top surface. By using both longitudinal and transverse piezoelectric effects of conformally-sputtered AlN layers on sidewalls and top surface of a 20 m thick resonator, a low(More)
— This letter reports, for the first time, on a high-frequency resonant square micro-gyroscope using piezoelectric transduction. Degenerate pairs of orthogonal flexural resonance modes are used to provide energy exchange paths for the Coriolis-based resonant gyroscope in response to z-axis rotation. Aluminum nitride thin films have been used to provide(More)
— In this paper, we present dual-mode (DM) AlN-on-silicon micromechanical resonators for self-temperature sensing. In-plane width-shear (WS) and width-extensional (WE) modes of [110]-oriented silicon resonators have been used as alternatives to first-and third-order modes to enhance DM temperature sensitivity by engineering device geometry, which reduces(More)
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