i have a momentum question too! - RF Cafe Forums

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guest

Post subject: i have a momentum question too! Posted: Mon Oct 10, 2005 2:54 am

Other EM software let you plot characteristic impedance and attenuation constant of a transmission line but I didn't see how you would accomplish that in Momentum! Is there a way to plot these two plus the effective permittivity vs. frequency in Momentum. Is there a good tutorial on that. The ADS help doesn't seem to cover this. Nice day!

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pallavi_d

Post subject: Momentum problemPosted: Mon Oct 10, 2005 7:19 am

Captain

Joined: Thu Oct 06, 2005 3:45 am

Posts: 7

Location: India

Hi,

As far as i know , its not possible to plot characteristic impedance and attenuation constant of a transmission line in momentum .I had also tried it , and had the same doubt some months back.

The answer i got was we need to use matlab for getting the plots.

If anyone out there knows the answer let me know too.

regards,

Pallavi

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guest

Post subject: Posted: Mon Oct 10, 2005 4:16 pm

i don't want to go through the matlab why...it's surprising that momentum won't let users easily plot attenuation constant while other CAD tools do. any way, gamma = alpha + jBeta where as all know alpha is the attenuation constant....meaning, you need the real part of gamma to get alpha

now momentum generates gamma and you can plot it, which for many designers isn't that useful because they're used to looking at alpha. but as with any plot ADS lets you plot real part of gamma Real(GAMMA) and the real of gamma which is supposedly alpha will be plotted. i did that but i do not think i got the right plot...the attenuation constant was almost zero ...e-17 order while all the other plots like s-param, characteristic impedance are normal and what i expected....try this and see if you get any sensible result and then let us know here...take care

Posted  11/12/2012