As far as I learned,there are three different definitions about quality factor(Q)
1.Q=energy stored/average power dissipation
2.Q=f(center)/gap of f(-3db)
3.Q=ω/2σ, for a pole loated at σ+jω
My question is that ,since all these three definitions are for the same guy,they must have something in common,what is that?
and why do we use different definitions,is there some different thing among these three definitions?
As far as I learned,there are three different definitions about quality factor(Q)
1.Q=energy stored/average power dissipation
2.Q=f(center)/gap of f(-3db)
3.Q=ω/2σ, for a pole loated at σ+jω
My question is that ,since all these three definitions are for the same guy,they must have something in common,what is that?
and why do we use different definitions,is there some different thing among these three definitions?
4.Q=f(center)/gap of f(7dB) of return loss if f(center) matched for maximum possible return loss.
(one of method to measure unloaded Q in ceramic resonator with only one port)
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You can find couple of definitions of Q - not only three...
but all of then handle ratio of reactive storage energy compare to dissipation in network itself or/and tapped/coupled energy to other connected network.
for example:
Q = X / R (ratio of reactive impedance compare to real impedance) is implement of point 1 and for inductance with unwanted serie resistance can give Q = (L*2*PI*f)/R
you have loaded Q with respect to coupled other network as load, and unload Q with ratio of reactive part and resistive part in network itself (for example resonator)