Frequecy interval and reflection coefficient

Altair Forum User

  Hi, I designed microstrip inset feed patch antenna but its reflection ceofficient changes with respect to frequency interval selection . Below,  there are 3 different frequency interval for the same design paramaters.

 Which parameter give me best results in fabrication or is there exist a rule to select frequecny interval to design antenna? What is the reason that cause this difference.

 

Johan_Huysamen

Hi celaleddin taylan

 

From your three images it looks like you have changed the frequency ranges, but kept the number of frequency samples the same. If you then reduce the range, you sample the frequency more finely.

 

The behavior you see is caused by the fact that the number of discrete frequency samples is insufficient to locate the minimum reflection coefficient. More samples (finer sampling) is required.

I would suggest that you try the 'Continuous (interpolated) range' option for the solution frequency:

 

 

With this option Feko will automatically sample a sufficient number ot frequency points to accurately locate the minimum value (at the resonance point).