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Saskatoon, Canada

Pelet E.R.,11 116 Research Drive | Salt J.E.,University of Saskatchewan
IEEE Transactions on Communications | Year: 2010

Recently, non-data aided synchronizers for QAM with a feedforward structure have been significantly improved by incorporating the prefilter originally proposed by Franks to mitigate the self-noise in analog clock regenerators. Prior to this, D'Andrea proposed a synchronizer with a feedback structure that used Franks' prefilter. Although not reported in the literature, the earlier D'Andrea's synchronizer outperforms the more recent feedforward synchronizers, and consequently is believed by the authors to be the optimum non-data aided synchronizer for QAM. An all digital version of D'Andrea's synchronizer is presented in this paper. The steady state timing jitter is thoroughly analyzed by deriving a closed form expression for the noise power spectrum, as well as a simple expression to estimate the variance of the jitter. Performance comparisons are made. © 2006 IEEE. Source

Kissling S.,Karlsruhe Institute of Technology | Bade K.,Karlsruhe Institute of Technology | Borner M.,Karlsruhe Institute of Technology | Klymyshyn D.M.,University of Saskatchewan | Klymyshyn D.M.,11 116 Research Drive
Microsystem Technologies | Year: 2010

High aspect ratio nickel radio frequency mi- croelectromechanical systems (RF MEMS) were fabricated by X-ray lithography and electroplating. Control of growth during electroforming of micro components is in general a problem in terms of achieving homogeneous thickness due to a non-uniform current distribution across a layout. It is necessary to level the deposited layer by means of a lapping process which results in burr formation. To ensure the functional properties of the devices these burrs have to be removed. Electropolishing with a current density of 80 A/dm is used for burr removal from nickel micro components containing small width (∼10 μm) structural elements. The investigated metal removal rates range from 0.2 to 1.8 μm/s depending on burr formation, presence or absence of resist and device position in the layout during electropolishing. Furthermore, edge rounding, a common electropolishing effect, is only observed when electropolishing in the absence of resist. © 2010 Springer-Verlag. Source

Jayatilaka H.C.,University of Saskatchewan | Jayatilaka H.C.,11 116 Research Drive | Klymyshyn D.M.,University of Saskatchewan | Klymyshyn D.M.,11 116 Research Drive | And 2 more authors.
Progress In Electromagnetics Research C | Year: 2011

A thick metal microstrip diplexer is presented. The ircuit is based on compact folded half wavelength resonators and uses source/load-multi-resonator coupling method providing improved erformance and greater design flexibility. Source/load coupling with ultiple resonators introduces additional transmission zeros, and this oupling is enhanced by using high-aspect-ratio metal structures. all, narrow metal arms connected to the ports and extended to he non-adjacent resonators provide effective multi-resonator bypass oupling. The high-aspect-ratio diplexer fabricated using polymer-based deep X-ray lithography and 0.22 mm thick metal electroplating emonstrates the advantages of thick metal structures for coupled esonator applications. Source

Klymyshyn D.M.,University of Saskatchewan | Klymyshyn D.M.,11 116 Research Drive | Mappes T.,Karlsruhe Institute of Technology | Achenbach S.,University of Saskatchewan | And 4 more authors.
Journal of Micromechanics and Microengineering | Year: 2010

X-ray lithography shadow projection using silicon nitride-based x-ray masks is used to fabricate sub-micron scale, high-aspect-ratio structures in thick polymer templates for surface acoustic wave (SAW) applications. Interdigital electrode patterns with 380 nm wide, free-standing polymer features are fabricated in 2 μm thick templates, representing an aspect ratio of 5.26:1. The tall and narrow polymer 'ribbons' run laterally in a serpentine arrangement of 114 electrodes over a large area of approximately 30 μm × 250 μm. Aluminum deposition and lift-off using the polymer templates are performed to construct metal electrodes for the verification of SAW resonator performance above 2.5 GHz. Environmental scanning electron microscopy and atomic force microscopy are used to inspect the metal electrode edge and surface topology, and demonstrate the feasibility of metal lift-off with highly vertical sidewall polymer templates for SAW applications. Such precise polymer templates could offer interesting possibilities for acoustic applications requiring thick and/or narrow electrodes and reflectors not only through more traditional metal deposition approaches but also as thick etch masks for metal removal. © 2010 IOP Publishing Ltd. Source

Haluzan D.T.,University of Saskatchewan | Haluzan D.T.,11 116 Research Drive | Klymyshyn D.M.,University of Saskatchewan | Klymyshyn D.M.,11 116 Research Drive | And 4 more authors.
Microsystem Technologies | Year: 2012

An efficient method is presented to determine the mechanical properties of thick metal layers using the pull-in voltage of electrostatically actuated structures. To fabricate these high aspect ratio beams without severe deformations, additional features were added, which made existing pull-in voltage equations inaccurate and therefore corrections were necessary. ANSYS Multiphysics was used to analyze the differences between ideal beams and the fabricated beams. To demonstrate the proposed approach, both nickel and gold devices were fabricated. To extract the material property values, a sum of least squares fitting scheme was used. A Young's modulus of 186.2 and 60.8 GPa was obtained for nickel and gold structures respectively. Both values are significantly smaller than values reported for bulk material, but fall within the range of values reported in the literature. © 2011 Springer-Verlag. Source

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