The Experts below are selected from a list of 329385 Experts worldwide ranked by ideXlab platform
Clark T C Nguyen - One of the best experts on this subject based on the ideXlab platform.
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series resonant vhf micromechanical Resonator reference oscillators
International Solid-State Circuits Conference, 2004Co-Authors: Sheng Shian Li, Clark T C NguyenAbstract:Series-resonant vibrating micromechanical Resonator oscillators are demonstrated using a custom-designed single-stage zero-phase-shift sustaining amplifier together with planar-processed micromechanical Resonator variants with quality factors Q in the thousands that differ mainly in their power-handling capacities. The Resonator variants include two 40-μm-long 10-MHz clamped-clamped-beam (CC-beam) Resonators, one of them much wider than the other so as to allow larger power-handling capacity, and a 64-μm-diameter 60-MHz disk Resonator that maximizes both Q and power handling among the Resonators tested. Trade-offs between Q and power handling are seen to be most important in setting the close-to-carrier and far-from-carrier phase noise behavior of each oscillator, although such parameters as resonant frequency and motional resistance are also important. With a 10× higher power handling capability than the wide-width CC-beam Resonator, a comparable series motional resistance, and a 45 x higher Q of 48 000, the 60-MHz wine glass Resonator reference oscillator exhibits a measured phase noise of -110 dBc/Hz at 1-kHz offset, and -132 dBc/Hz at far-from-carrier offsets. Dividing down to 10 MHz for fair comparison with a common conventional standard, this oscillator achieves a phase noise of -125 dBc/Hz at 1-kHz offset, and -147 dBc/Hz at far-from-carrier offsets.
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frequency selective mems for miniaturized low power communication devices
IEEE Transactions on Microwave Theory and Techniques, 1999Co-Authors: Clark T C NguyenAbstract:With Q's in the tens to hundreds of thousands, micromachined vibrating Resonators are proposed as integrated circuit-compatible tanks for use in the low phase-noise oscillators and highly selective filters of communications subsystems. To date, LF oscillators have been fully integrated using merged CMOS/microstructure technologies, and bandpass filters consisting of spring-coupled micromechanical Resonators have been demonstrated in a frequency range from HF to VHF. In particular, two-Resonator micromechanical bandpass filters have been demonstrated with frequencies up to 35 MHz, percent bandwidths on the order of 0.2%, and insertion losses less than 2 dB. Higher order three-Resonator filters with frequencies near 455 kHz have also been achieved, with equally impressive insertion losses for 0.09% bandwidths, and with more than 64 dB of passband rejection. Additionally, free-beam single-pole Resonators have recently been realized with frequencies up to 92 MHz and Q's around 8000. Evidence suggests that the ultimate frequency range of this high-Q tank technology depends upon material limitations, as well as design constraints, in particular, to the degree of electromechanical coupling achievable in microscale Resonators.
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an integrated cmos micromechanical Resonator high q oscillator
IEEE Journal of Solid-state Circuits, 1999Co-Authors: Clark T C Nguyen, Roger T HoweAbstract:A completely monolithic high-Q oscillator, fabricated via a combined CMOS plus surface micromachining technology, is described, for which the oscillation frequency is controlled by a polysilicon micromechanical Resonator with the intent of achieving high stability. The operation and performance of micromechanical Resonators are modeled, with emphasis on circuit and noise modeling of multiport Resonators. A series resonant oscillator design is discussed that utilizes a unique, gain-controllable transresistance sustaining amplifier. We show that in the absence of an automatic level control loop, the closed-loop, steady-state oscillation amplitude of this oscillator depends strongly upon the dc-bias voltage applied to the capacitively driven and sensed /spl mu/Resonator. Although the high-Q of the micromechanical Resonator does contribute to improved oscillator stability, its limited power-handling ability outweighs the Q benefits and prevents this oscillator from achieving the high short-term stability normally expected of high-Q oscillators.
Mohammad Ibrahim YOUNIS - One of the best experts on this subject based on the ideXlab platform.
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Efficient Excitation of Micro/Nano Resonators and Their Higher Order Modes
Scientific Reports, 2019Co-Authors: Nabih Jaber, M. H. Hasan, Shaista Ilyas, Md Adbdullah Al HAFIZ, S. N. R. Kazmi, F. Alsaleem, Mohammad Ibrahim YOUNISAbstract:We demonstrate a simple and flexible technique to efficiently activate micro/nano-electromechanical systems (MEMS/NEMS) Resonators at their fundamental and higher order vibration modes. The method is based on the utilization of the amplified voltage across an inductor, L, of an LC tank resonant circuit to actuate the MEMS/NEMS Resonator. By matching the electrical and mechanical resonances, significant amplitude amplification is reported across the Resonators terminals. We show experimentally amplitude amplification up to twelve times, which is demonstrated to efficiently excite several vibration modes of a microplate MEMS Resonator and the fundamental mode of a NEMS Resonator.
Roger T Howe - One of the best experts on this subject based on the ideXlab platform.
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an integrated cmos micromechanical Resonator high q oscillator
IEEE Journal of Solid-state Circuits, 1999Co-Authors: Clark T C Nguyen, Roger T HoweAbstract:A completely monolithic high-Q oscillator, fabricated via a combined CMOS plus surface micromachining technology, is described, for which the oscillation frequency is controlled by a polysilicon micromechanical Resonator with the intent of achieving high stability. The operation and performance of micromechanical Resonators are modeled, with emphasis on circuit and noise modeling of multiport Resonators. A series resonant oscillator design is discussed that utilizes a unique, gain-controllable transresistance sustaining amplifier. We show that in the absence of an automatic level control loop, the closed-loop, steady-state oscillation amplitude of this oscillator depends strongly upon the dc-bias voltage applied to the capacitively driven and sensed /spl mu/Resonator. Although the high-Q of the micromechanical Resonator does contribute to improved oscillator stability, its limited power-handling ability outweighs the Q benefits and prevents this oscillator from achieving the high short-term stability normally expected of high-Q oscillators.
Teng Li - One of the best experts on this subject based on the ideXlab platform.
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Resonant frequency of gold/polycarbonate hybrid nano Resonators fabricated on plastics via nano-transfer printing.
Nanoscale research letters, 2011Co-Authors: Edward Dechaumphai, Nathan P Siwak, Reza Ghodssi, Zhao Zhang, Teng LiAbstract:ABSTRACT: We report the fabrication of gold/polycarbonate (Au/PC) hybrid nano Resonators on plastic substrates through a nano-transfer printing (nTP) technique, and the parametric studies of the resonant frequency of the resulting hybrid nano Resonators. nTP is a nanofabrication technique that involves an assembly process by which a printable layer can be transferred from a transfer substrate to a device substrate. In this article, we applied nTP to fabricate Au/PC hybrid nano Resonators on a PC substrate. When an AC voltage is applied, the nano Resonator can be mechanically excited when the AC frequency reaches the resonant frequency of the nano Resonator. We then performed systematic parametric studies to identify the parameters that govern the resonant frequency of the nano Resonators, using finite element method. The quantitative results for a wide range of materials and geometries offer vital guidance to design hybrid nano Resonators with a tunable resonant frequency in a range of more than three orders of magnitude (e.g., 10 KHz-100 MHz). Such nano Resonators could find their potential applications in nano electromechanical devices. Fabricating hybrid nano Resonators via nTP further demonstrates nTP as a potential fabrication technique to enable a low-cost and scalable roll-to-roll printing process of nanodevices.
Roberto R Panepucci - One of the best experts on this subject based on the ideXlab platform.
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tunable silicon microring Resonator with wide free spectral range
Applied Physics Letters, 2006Co-Authors: M S Nawrocka, Xuan Wang, Roberto R PanepucciAbstract:The authors present a silicon-on-insulator single ring Resonator with a free spectral range equal to 47nm, which is the widest known value for this type of Resonators. The ring radius is 2μm and is the smallest ring Resonator ever reported, achieving experimentally such a wide spectral range. For this ring Resonator, the authors demonstrate the quality factor to be equal to 6730±60. They thermally tune the resonant wavelength with 0.11nm∕°C, thus showing the ring Resonator as an attractive component for on-chip ultracompact photonic add/drop filters and switches.
