To optimize hairpin bandpass filter in HFSS

[nehal02]

I am working on optimizing a Hairpin Bandpass Filter (BPF) using HFSS but am unable to achieve the specified goals. I have attached both the simulation results and the desired results for reference,goal expression and variables . Could someone guide me on what might be going wrong?

 

[volker@muehlhaus]

I can't help with HFSS, but some general comments:

1) I would remove the S21 goal for pass band, that is already optimized by the S11 passband goal.
2) Does negative length makes sense in your design? It will help to start from good starting values, e.g. the values from ADS.