Multiple Band Notched Filter Using C-Shaped and E-Shaped Resonator for UWB Applications

In this letter, a highly selective ultra wide band (UWB) band pass filter (BPF) with triple notch bands is proposed using C-Shaped and E-Shaped resonators along with a triangular ring loaded stub resonator (TRLSR) resting on a multi-mode resonator (MMR). The MMR is constructed using a uniform transmission line and parallel coupled lines connected to 50 Ω feed lines at both ends. Five even and odd modes are created to achieve an UWB passband response. Additionally, two transmission zeros at lower and upper cutoff frequencies of the passband are formed by TRLSR which helps to get a high skirt factor (SF) of 0.975. In addition, multiple notch bands are created using λ
_g
/2 resonators to reject three interfering frequency bands named as WiMAX, WLAN, and X-Band. The center frequency of each notch can be controlled by tuning the length of the resonator. The proposed filter is simulated, fabricated, and tested experimentally. Both the predicted and the measured results are in good agreement and replicating the behavior of the proposed filter.