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mike_ok

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how to measure Q of an inductor in cadence?
Mar 19^th, 2008, 1:01am

Hi, everyone!

this is my first time to start new topic and i hope that some will help me.
my questions is that in cadence evironment, how to measure the qulity of inductors and its inductance.
as is well know that the expession"Q=[Im(1/Y11)]/[Re(1/Y11)]" and "L=[im(1/Y11)]/[2*pi*freq]" in ADS environment can solve my questions, but in cadence,i don't know how to write the above exprssion, because i cannot find the term of Y11.
your help will be aprreciated!
thanks!

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pancho_hideboo Senior Fellow Offline Posts: 1424 Real Homeless	Re: how to measure Q of an inductor in cadence? Reply #1 - Mar 19^th, 2008, 1:54am See http://www.designers-guide.org/Forum/YaBB.pl?num=1196459940
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Frank Wiedmann Community Fellow Offline Posts: 678 Munich, Germany	Re: how to measure Q of an inductor in cadence? Reply #2 - Mar 19^th, 2008, 3:22am You should also be aware of the fact that there exist different definitions for the quality factor of an inductor. Depending on your application, some of them may be more useful for you than others. Please see http://www.simics.tec.ufl.edu/papers/00705364.pdf for details.
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mike_ok New Member Offline Posts: 3	Re: how to measure Q of an inductor in cadence? Reply #3 - Mar 19^th, 2008, 5:08am thank you for your replies! now i still not know the details on how to implemet the term"y11", in my CIW, it says "y11,an unbound varication" or some one give me more details on mearsure the Q and L? Thanks a lot ,my dear friends!
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ACWWong Community Fellow Offline Posts: 539 Oxford, UK	Re: how to measure Q of an inductor in cadence? Reply #4 - Mar 19^th, 2008, 6:13am after you have run an sp analysis y11 is available as: yp(1 1 ?result "sp") you can easily use the calculator to access these, more details will be in the cadence documentation. also note as shown in the example given by pancho_hideboo, you'll need xval() to get the frequency term.
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RFICDUDE

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Re: how to measure Q of an inductor in cadence?
Reply #5 - Mar 19^th, 2008, 4:20pm

A simple simulation technique is to use a 1A AC current source (DC=0A) across the inductor then you can measure the impedance of the inductor directly as the AC voltage across the inductor.

Z=re(Vac)+j*imag(Vac)

Y=1/Z

I like to look at all of these parameters when evaluating integrated inductors

Rs(f) = re(Vac)

Rp(f)=1/re(1/Vac)

Q(f)=imag(Vac)/re(Vac)

L(f)=imag(Vac)/(2*PI*xval(Vac))

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mike_ok New Member Offline Posts: 3	Re: how to measure Q of an inductor in cadence? Reply #6 - Jun 26^th, 2008, 11:37pm thank you, your methody is great!
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