Analysis and design of bandstop filter using E-shaped dual mode resonator

This paper reports analysis and design of bandstop filter utilizing E-shaped dual mode resonator. The basic structure of the bandstop filter consists of E-shaped resonator parallel to microstrip transmission line and an open stub inverter. Parametric analysis is carried out using Micro-Stripes software and the design is optimized to get stop band with high rejection level at 6 GHz centre frequency. Simulated and measured results of both single and double dual mode resonator bandstop filters are presented. Simulations of the bandstop filter using both edge-coupled and the side- coupled resonators are also reported. No significant improvement in the characteristics of bandstop filters using edge-coupled design was observed. However, side-coupled design showed remarkable improvement in the stop band characteristics as compared with the single resonator bandstop filter. The experimental and simulated results presented show good agreement.