YCChiou
Junior Member level 3
Hi All:
We sometimes want our filter to have better selectivity so we will try to add transmission zeros at higher or lower bands. When I read the paper, they would use additional open stub or parallel-resonance to locate zeros at specific frequency; however, it usually accompanies with radiation loss. (We may see |S11|^2+|S21|^2<1; for instance the |S11| = -7 dB and |S21|=-30 dB at that frequency.) I'm wondering how to eliminate it? Could we add some metal in the top of circuit?
Thank you
We sometimes want our filter to have better selectivity so we will try to add transmission zeros at higher or lower bands. When I read the paper, they would use additional open stub or parallel-resonance to locate zeros at specific frequency; however, it usually accompanies with radiation loss. (We may see |S11|^2+|S21|^2<1; for instance the |S11| = -7 dB and |S21|=-30 dB at that frequency.) I'm wondering how to eliminate it? Could we add some metal in the top of circuit?
Thank you
