The Designer's Guide Community Forum https://designers-guide.org/forum/YaBB.pl Modeling >> Passive Devices >> Capacitor simulation https://designers-guide.org/forum/YaBB.pl?num=1222649062 Message started by gorkhim on Sep 28th, 2008, 5:44pm

 Title: Capacitor simulation Post by gorkhim on Sep 28th, 2008, 5:44pm I am trying to estimate the equivalent series resistance, quality factor and capacitance for a MIM capacitor in 90nm process technology using S-parameter analysis in Cadence IC5141.After running the analysis, I am using the Y-parameters to plot the G, C & Q using the following equations:1. G =  real(Y11 - ((Y12*Y21)/Y22))2. C = -imag(Y11 - ((Y12*Y21)/Y22))/(2*pi*f)3. Q= -imag(Y11 - ((Y12*Y21)/Y22))/real(Y11 - ((Y12*Y21)/Y22))The plot for these equations is attached. These plots are not making any sense. Does anyone have any clue about what am I doing wrong? Also when I use a similar test-bench for an inductor, these equations works properlyThanks.

 Title: Re: Capacitor simulation Post by Berti on Sep 28th, 2008, 11:58pm Unfortunately, your graphic is hardly readable.However, are you sure that the MIM capacitor model includes a series resistance.In the DK I am using, the no series resistance is modeled for the MIM capacitor, unlessyou add it from parasitic extraction.Regards

 Title: Re: Capacitor simulation Post by gorkhim on Sep 30th, 2008, 1:59pm Thank you for your quick response. Yes there was wrong model file.

 Title: Re: Capacitor simulation Post by ywguo on Dec 12th, 2008, 1:29am Hi gorkhim,Why do you measure the Q/G/C with 2 ports. It is one port for a varactor actually. The formula is simpler if simulating with one port.1. G = real(Y11)2. C = imag(Y11)/(2*pi*f)3. Q= imag(Y11))/real(Y11)Yawei