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gopt, gmin and Bmin (Read 2533 times)

R. Zakai

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gopt, gmin and Bmin
Sep 23^rd, 2006, 6:24am

Does anyone know why 1/gopt obtained through the results browser would not match the Real(Rs*(1+Gmin)/(1-Gmin)) obtained through the calculator. They should be the same if Gmin is optimum noise figure input reflection coefficient and gopt is optimum noise conductance.

I have the same problem with 1/Bopt obtained through the results browser not matching the Imag(Rs*(1+Gmin)/(1-Gmin)).

Appreciate any comments.
Rehan

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Tawna Wilsey

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Snohomish, WA

Re: gopt, gmin and Bmin
Reply #1 - Apr 11^th, 2007, 3:20pm

The equations behind the various plotting options in the Direct Plot form are detailed in the SpectreRF User Guide Appendix E. Plotting S-Parameter Simulation Data. Theoretically, the equations accessed via the direct plot form should be the same as those accessed via the calculator/results browser.

Note that there are some caveats to watch out for...e.g., when you plot GT (transducer gain), there is an assumption made that Gamma-L and Gamma-S are zero. Which means you are basically plotting |S21|^2

best regards,
tawna

Tawna Wilsey

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