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Design >> RF Design >> quality factor of inductor
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Message started by Julian18 on Oct 27^th, 2008, 8:51am

Title: quality factor of inductor
Post by Julian18 on Oct 27^th, 2008, 8:51am

Hi,
after reading a lot of papers, I am totally confused by the definition of quality factor of inductor. That is , should we take the electric energy that is inevitably stored in a real inductor into the account? if so should that form of energy be added to or subtracted from the dominant magnetic energy stored in the inductor. If the former is the correct definition, we should get the same definition of Q of an inductor as that of a resonator, If the latter is correct, we get the commonly used formula Q = -Im(y11)/Re(y11).

Thanks.

Julian

Title: Re: quality factor of inductor
Post by Frank Wiedmann on Oct 27^th, 2008, 10:00am

You can find a good overview over different definitions for the quality factor of inductors and their usefulness for circuit design in http://www.simics.tec.ufl.edu/papers/00705364.pdf.

Title: Re: quality factor of inductor
Post by raja.cedt on Nov 12^th, 2008, 9:04pm

hi ,
i have one doubt regarding Q factor of a circuit.generally i heard Q is defined for 2nd order system only,is this true?i saw in one razaavi paper,in that he used to find Q factor for any circuit by using the standard definition Q=ω*.5*(dΦ/dw)(i hope u understood the formula),in the above expression ω means resonance frequency or corner frequency.Instead he used direct ω as variable frequency.the following is the paper

http://www.ee.ucla.edu/~brweb/papers/Journals/BRSept08.pdf
just refer appendix-1

Thanks for your time.
Regards,