loaded, unloaded and external quality factor

Dear friends?
What is the difference between unloaded quality factor QU and loaded quality factor QL? In Ansoft HFSS, which knid of quality factor can be calculated, QU or QL?
Thank you!

Hi Sophianining
If you have read the answer to your previous question about Q, the unloaded Q is the one you get if you do not connect any external load to the resonant circuit. All these kinds of Qs are related by the equation

1/QL=(1/Qe)+(1/Q)

no matter of parallel or serial RLC circuit

Thank you very much Vtrs.
I have another question to ask:
Taking a four cavity resonator filter for example, we can calculate the coupling matrix M and source/load resistance R of the filter, then, I'd like to know what is the corresponding quantity of R? Is it the external quality factor Qe ---- the external quality factor we get when we connect a resistance R to the terminal of the filter?
Thank you again.

"four cavity resonator filter"? Can you be more specific about your device?
Thanks

I have affixed the "Four cavity filter " model , you can check it for more detailed information.
Thank you.

how to obtain unloaded Q?
Thanks