yorkyong
Junior Member level 3
My design is a hairpin microstrip bandpass filter. fc=3G BW=300M
I think it can be considered as a lossless passive circuit
BUT...
where out ot pass band, S11 is about 0db and S21 is about -30db or more
where in the pass band, S11 is -10db and S21 is -13db!!!
what a great insertion loss!
the shape of db(S21) curve is nice, and insertion loss is the only problem. Network Analyzer was well calibrated.
How can I explain that |S11|^2+|S21|^2 much less than 1 within passband? And where the energy has gone?
I think it can be considered as a lossless passive circuit
BUT...
where out ot pass band, S11 is about 0db and S21 is about -30db or more
where in the pass band, S11 is -10db and S21 is -13db!!!
what a great insertion loss!
the shape of db(S21) curve is nice, and insertion loss is the only problem. Network Analyzer was well calibrated.
How can I explain that |S11|^2+|S21|^2 much less than 1 within passband? And where the energy has gone?