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...nd 377 are often required. Among the most direct methods for lowering the motional resistance of capacitively transduced micromechanical resonators are: 1) scaling down the electrode-to-resonator gap =-=[7]-=-; 2) raising the dc-bias voltage; and 3) summing together the outputs of an array of identical resonators [8]. Unfortunately, each of these methods comes with drawbacks. In particular, although the fi...

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... extensional wine-glass ring is governed by the total integrated kinetic energy in the resonator, by its mode shape, and by parameters associated with its transducer ports [6]. Using the procedure of =-=[7]-=-, an approximate expression for the equivalent series motional resistance R x of an extensional wine-glass ring resonator can be obtained. For an electrode configuration as in Fig. 4(b), with ports 1 ...

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...om such inner electrodes, thereby reducing the factor by which the motional resistance is lowered. A more detailed determination of Rx using velocity integration over each electrode (e.g., as done in =-=[10]-=-) yields reduction ratios of 1.84, 2.85, and 4.94, for the 3, 5, and 9 resonator arrays, respectively, which now match the measured values. Note that the square resonators of [7] did not suffer from t...

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...grated (MSI) mechanical circuit on a chip. I. INTRODUCTION To date, on-chip mechanical filters comprised of several micromechanical resonators, coupled either mechanically via soft mechanical springs =-=[1]-=-; or electrically, using parallelresonator architectures [2], ladder networks [3], or coupling capacitors [4]; have been demonstrated with impressive frequency characteristics. However, the recent des...

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...ers were demonstrated early in literature [30]; later, higher frequency MEMS filters with frequencies around 7.8 MHz and percent bandwidths from 0.2% to 2.5% (Q from 40 to 450) were also demonstrated =-=[31]-=-. Unfortunately, filters working at much higher frequencies are still needed for useful implementation in communication systems, in particular at RF range [11], [32]. This paper focuses on frequencies...

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...ators that satisfy GSM specifications [8][9]; and have comprised the key resonator elements in micromechanical filters with record low on-chip insertion losses for tiny percent bandwidth applications =-=[10]-=-[11]. Despite these recent successes, there are still a few remaining issues that should be resolved before vibrating RF MEMS technology can realize its true potential in mainstream RF markets. These ...

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...781, is as good as the prior art [7]. The anchor loss is known to dominate the Q performance of the CC-beam resonators [20]. In comparison with the Q performance of the polysilicon CC-beam resonators =-=[21]-=-, the lower Q performance of the Ni-based resonators may be a result of poor adhesion of the beam anchors to the substrate underneath, leading to more energy dissipation during vibration [7]. Further ...

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...ating multiband and multistandard devices that consume low power and have small form factors will accomplish the vision of next-generation, ubiquitous wireless communications. Several research groups =-=[1]-=-–[7] have demonstrated coupled electrostatically driven microresonators for filtering applications. Although characterized by very high Q, these microdevices suffer from large motional resistance, . F...

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.... However if the electrode is placedsalong the beam and at the free end, the beam vibrates longitudinally.s96sTable 9sSummary of vibrating shapessResonator types DescriptionsPerformancesClamp – clamp =-=[93]-=- An electrode is placed insplane or under thesclamp – clamp beam tosform transducerscapacitor.s1 MHz - 100MHz; Qsdegraded due to anchorsdissipation at highsfrequency.sClamp – free [94] The clamp can b...