A fully tunable C-band reflectionless bandstop filter using L-resonators

This paper presents a fully tunable reflectionless bandstop filter using multi-section L-Resonators. The bandstop filter is designed to operate in the C-Band, tunable from 3.96-4.4 GHz with greater than 20 dB of in-band rejection and a return loss of better than 8 dB across the full tuning range. Simulation and measurement results are presented.