Output Section - Stored Energy or QL


How much power a filter can handle before break-down occurs is dependent on factors like pressure, temperature, resonator geometry, unloaded Q, return loss, topology, frequency, signal dynamics (modulation, duty-cycle, prf) etc.
 
The stored energy of a resonator is proportional to the square of the peak electric field strength of the resonator.
 
  • In CMS the stored energy (or equivalent - the loaded Q) for each resonator can be plotted versus frequency. 
    The calculated stored energy levels in CMS are normalized to 1 W applied at the input.
  • This feature allows the filter designer to optimize designs with respect to power handling.
  • It is possible to specify the load returnloss in the QL graph, whereby the axes values are scaled correspondingly. The values are scaled assuming worst case phase conditions between filter and load.
  • The curve values can be read out by moving the mouse cursor around in the plot
  • CMS pinpoints the resonator(s) where break-down will occur first and also the corresponding stored energy.
    This energy can easily be scaled to power levels other than 1W
 
Loaded Q and stored energy (10-9J/Watt) for each resonator in the filter.

 

 

 

 

 

 

 
 More information on power handling analysis of Rf filters can be found on the CMS web site's example and in [6] & [7].
The graphs can be arranged by changing the values on the axes.
Curve values can be red out by inserting markers.

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