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The use of active feedback in closed-loop with two electrodes of a four-electrode capacitive-gap transduced wineglass disk resonator has enabled boosting of the effective resonator Q and independent control of insertion loss across the two other electrodes. To demonstrate the utility of this approach, two such Q-boosted resonators wired as a parallel-type micro-mechanical filter achieve a tiny 0.001%...
A 61-MHz Pierce oscillator referenced to a single polysilicon surface-micromachined wine-glass disk resonator has achieved phase noise marks of −119dBc/Hz at a 1-kHz offset and −139dBc/Hz at far-from-carrier offsets. When divided down to GSM's 13MHz, this corresponds to −132dBc/Hz at 1-kHz and −152dBc/Hz at far-from-carrier offsets, both of which satisfy GSM reference oscillator phase noise requirements...
RF MEMS technologies are evaluated with regard to their potential to realize the RF frequency gating function targeted for true software-defined cognitive radios and ultra-low power autonomous sensor network radios. Here, RF channel-selection, as opposed to band selection, is key to substantial increases in call volume with simultaneous reduction in power consumption. The MEMS technologies most conducive...
A micro-scale mechanical charge pump, cf. Fig. 1(a), comprising a circuit of micromechanical resonant switches (a.k.a., resoswitches) has been demonstrated that generates 3V and 9V from 1V and 3V power supplies, respectively, using a 2-stage design; and 6V from 1V supply using a 5-stage design; all while avoiding the diode voltage drop and breakdown voltage limitations of conventional CMOS-based charge...
A capacitive-comb transduced micromechanical resonator using aggressive lithography to occupy only 0.0154-mm2 of die area has been combined via bond-wiring with a custom ASIC sustaining amplifier and a supply voltage of only 1.65V to realize a 32.768-kHz real-time clock oscillator more than 100× smaller by area than miniaturized quartz crystal implementations and at least 4× smaller than other MEMS-based...
A low phase noise oscillator referenced to a 61-MHz vibrating wine-glass disk resonator with anchor-isolating supports designed to suppress microphonics has posted (without any compensation) a measured acceleration sensitivity at least as good as Γ ∼0.2ppb/g for vibration frequencies up to 2kHz and in all directions, yielding a vector magnitude Γ less than 0.5ppb/g. Remarkably, this result is at least...
A capacitive-gap transduced micromechanical ring resonator based on a radial contour vibration mode and constructed from hot filament CVD boron-doped microcrystalline diamond has achieved a Q of 42,900 at 2.9685GHz that represents the highest series-resonant Q yet measured at this frequency for any on-chip room temperature resonator, as well as the highest f·Q of 1.27×1014 for acoustic resonators,...
A micromechanical displacement amplifier comprising two asymmetric resonator array composites coupled by a quarter-wavelength beam has been demonstrated that permits specification of gain factor by mere (digital) selection of an appropriate ratio of the number of resonators in an input array to that in an output array. Like the method, this displacement gain circuit is a key enabler for resoswitch-based...
A mechanical circuit-based approach for boosting the Q of a vibrating micromechanical resonator has been demonstrated whereby a low Q resonator is embedded into a mechanically-coupled array of much higher Q resonators to raise its functional Q by a factor approximately equal to the number of resonators in the array. Using this method, the low Q of 7,506 exhibited by a support-loss-limited 60- MHz...
Having now produced devices with sufficient Q, thermal stability, aging stability, and manufacturability, vibrating RF MEMS technology is already finding its way into next generation timing and wireless applications. At this juncture, the technology is now poised to take its next logical steps: higher levels of circuit complexity and integration. In particular, as vibrating RF MEMS devices are perceived...
Substantial reductions in vibrating micromechanical resonator series motional resistance Rx have been attained by mechanically coupling and exciting a parallel array of corner-coupled polysilicon square plate resonators. Using this technique with seven resonators, an effective Rx of 480 Omega has been attained at 70 MHz, which is more than 5.9X smaller than the 2.82 kOmega exhibited by a stand-alone...
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