Design of Wideband Band Stop Filter using Signal Interference Technique

A wideband band stop filter based on signal interference technique has been designed. The proposed filter is designed using coupled line and stepped impedance modified pi type transmission line with open circuited stubs in transmission path 1 and path 2 respectively. The proposed filter has been designed at a frequency of 0.9 GHz. The simulated 3dB fractional bandwidth is 0.8GHz and the insertion loss is well below -18dB or -20dB from 0.2 GHz to 2.14 GHz. Using path 2 ABCD parameters of the filter are found and these equations were solved to obtain the position of zeros