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L&R Extraction

Amir2162

I would like to know if stubs in the nets will also be covered by Inductance-Extraction of Clarity 3D Software. 
Please see example image below.
What I know is Inductance Extraction has SINK and SOURCE and this is the pathway of the signal to be simulated, but does it also pass on the stubs?
I want to know the inductance of the net from sink and source including the stubs for impedance matching checking.

Thank you very much

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  • JavierAlvarado
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    Hi Amir2162,

    Inductance workflow provides a Quasi-Static-solver-based inductance extraction in Clarity 3D Layout. It means that results are only valid under Quasi-static regime.

    A real transmission line (interconnect) when is open at the far end will look like an ideal capacitor at low frequency. At the other hand, when the far end of the transmission line is shorted, the transmission line looks like two wires, current could travel down the length of the signal wire and then return on the return path. This is a loop, and we can derivate the inductance of this signal-return path loop.

    These are important properties of any real transmission line. They indicate that at sufficiently low frequency, a real transmission line looks like ideal RLGC elements, but only up to a specific frequency. The valid frequency is before the first resonant frequency point, when the transmission line is one quarter of a wavelength. In other words, this is the limit of the Quasi-static regime.

    Stubs resonant frequency nulls happen at one quarter of a wavelength of a stub. Stubs are smaller than the transmission line (source to sink pathway) meaning stubs resonant frequency will appear far away the transmission line's first resonant frequency point, and of course, far away of Quasi-static regime.

    Under Quasi-static regime, stubs effects are transparent (negligible), but they are not at high frequency. 

    Regards,

    Javier

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