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Abstract-A new technique to de-embed the contributions of parasitic structures from transmission line measurements is presented and applied to microstrip lines fabricated in 90-and 130-nm RF-CMOS technologies. De-embedded measurements are used to extract characteristic impedance, attenuation constant, group delay, and effective permittivity. The effective thickness of the ground plane is demonstrated to be as important as the thickness of the top metal layer in minimizing interconnect loss. Furthermore, it is confirmed that metal area densities as low as 65% are adequate for the ground plane of microstrip lines.

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Reduced-order models have been reported in the literature that can be used to predict the harmonic response of mistuned bladed disks. It has been shown that in many cases they exhibit structural fidelity comparable to a finite element analysis of the full bladed disk system while offering a significant improvement in computational efficiency. In these models the blades and disk are treated as distinct substructures. This paper presents a new, simpler approach for developing reduced-order models in which the modes of the mistuned system are represented in terms of a subset of nominal system modes. It has the following attributes: the input requirements are relatively easy to generate; it accurately predicts mistuning effects in regions where frequency veering occurs; as the number of degrees-of-freedom increases it converges to the exact solution; it accurately predicts stresses as well as displacements; and it accurately models the deformation and stresses at the blades’ bases.

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