RF-filter loaded quality factor?

[erno]

Does anyone remember the way to determine the RF-filter loaded Q-values? I mean the loaded Q of every individual resonator.

Regards

Erno

 

[jiripolivka]

Most RF filters use low-loss, high-Q resonators, while their tuning and coupling according to calculated model defines their frequency response.
Any loss contributes to pass-band loss, usually not desired.
There is a class of filters using lossy resonators with which a special frequency/loss response can be adjusted.

 

[erno]

Let's have a five section filter with an unloaded Q of 1000. Passband 980-1000 MHz. Coupling matrix :
MS,1=0.021862
M1,2=0.01939
M2,3=0.014682
M3,4=0.01939
ML,4=0.021862

External quality faxtor of input and output 42.27
CBW12=19.2 MHz
CB23=14.53 MHz
CB34=19.2 MHz

So how do I derive the loaded Q of resonators 2 to 4?

Erno

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Sorry, It is a 4-section filter not five. Individual loaded Q of resonators of 2 and 3 would be of interest?

Erno