Now showing 1 - 2 of 2
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    Publication
    A parameterized cell design for high-Q, variable width and spacing spiral inductors
    (01-01-2014)
    Manikandan, R. R.
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    Vanukuru, Venkata Narayana Rao
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    Amrutur, Bharadwaj
    The on-chip planar spiral inductors having variable width (W) and spacing (S) across their turns are known to exhibit higher quality factors (Q). In this paper, we present an efficient parameterized cell (pcell) design in cadence using SKILL scripts for automatic layout generation of these complex, high-Q, variable W&S spiral inductors comprising of single ended and symmetric structures with rectangular, hexagonal, octagonal and circular spirals. Electromagnetic simulations are performed on the inductor layouts generated using the developed pcells. The constant W&S and variable W&S spiral inductor structures are fabricated in a 0.18 μm silicon on insulator process. Measurements show ∼25% improvement in the quality factor of variable W%S spiral inductors compared to their constant W&S counterparts and also validates the proper operation of the developed inductor parameterized cells. The presented variable W&S inductor pcell significantly reduces the layout design time of RF circuit designers and also helps in the design automation of these complex inductor structures to boost their own performance and the RF circuits as well.
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    Publication
    Compact Modeling of Proximity Effect in High- Q Tapered Spiral Inductors
    (01-04-2018)
    Sathyasree, J.
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    Vanukuru, Venkata
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    Nair, Deleep
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    This letter presents a technique to accurately predict the proximity effect losses in spiral inductors with variable width and spacing (taper) across the turns. The change in magnetic flux in a spiral turn due to the nearby non-uniformly spaced traces is considered while developing expression that captures proximity effect. A broadband, scalable, and frequency-independent compact model is developed for tapered inductors using the proposed technique. Resistance, inductance, and quality factor plots are shown for spiral inductors with different values of taper. Excellent agreement between model and EM simulated/measured data demonstrates the scalability of the proposed model. The proposed model can be used to accurately predict the high possible with tapered inductors.