Q help! - RF Cafe Forums

RF Cafe Forums closed its virtual doors in late 2012 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2012, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. Regardless, there are still lots of great posts in the archive that ware worth looking at. Below are the old forum threads, including responses to the original posts. Here is the full original RF Cafe Forums on Archive.org

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spbhu

Post subject: Q help! Posted: Mon Aug 08, 2005 6:39 am

Lieutenant

Joined: Tue Aug 02, 2005 1:44 am

Posts: 3

Location: NTU

People always say a high-Q peaking inductor or low high-Q peaking inductor? What does it mean? What does Q stand for, and high Q better or low Q better?

Thanks

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IR

Post subject: Posted: Mon Aug 08, 2005 11:52 am

Site Admin

Joined: Mon Jun 27, 2005 2:02 pm

Posts: 373

Location: Germany

Hello spbhu,

Q stands for Quality Factor. It defines the ratio between the energy that is being lost on power dissipation per cycle to the entire energy of the cycle. Another way to put it is:

Qul=Xl/R (Unloaded Quality Factor)

Where:

Xl - The reactance of the inductor (2*pi*f*L)

R - The ohmic resistance of the inductor's wire.

High Q is better since it means that there is a lower resistive dissipation in the inductor. There are few ways to achieve that like using air core or lower resistance materials for the wire.

_________________

Best regards,

- IR

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Guest

Post subject: Posted: Mon Aug 08, 2005 11:53 am

Q (Quality factor) is the ratio of reactive power to resistive power in a tuned circuit.

Posted  11/12/2012