hiii.... im designing a narrow bandpass filter using dual behavior resonators ..I m successful in getting my desired band during simulation in both ADS and CST softwares..but while fabricating there is a frequency shift in the band ... and im getting more return loss...how can i get rid of this??? help me out plz...
There's many reasons to have a frequency shift in your filter. Most of them relate to non-ideal material and construction. Your trace width will not be exactly 10mil (or whatever width). Your capacitors will not be exactly 5pF (or what ever value). Loading also comes into play with filters. You will need to provide more information for anyone to help.