Bandstop filter with improved Q factor using novel open-loop patch loaded slotline

A novel patch-shaped patch loaded slotline (PLS) to provide a band-rejection property with an improved Q factor is proposed in this paper. It has size of only 28% of conventional dumbbell PLS unit section and 72% of the conventional open-loop PLS unit section, while the Q factor is more than 10.5 times than dumbbell PLS and 3.3 times than the conventional open-loop PLS at the same resonant frequency of 33 GHz. High Q bandstop filters based on the newly proposed PLS with two and three sections are designed and simulated. Both filters have sharp cutoff frequency and high attenuation in the stopband.