CB-CPW based Wide Band Bandpass Filter using Open-Stub Resonator

Abstract

In this paper one conductor back coplanar waveguide based wide band bandpass filter is designed with end-coupled λ/4 open-stub resonator at the operating frequency 2.5 GHz. This proposed BPF structure exhibits negligible passband insertion loss of 0.2 dB, 100 % fractional bandwidth at −3 dB, sharp transition from passband to stopband, wide attenuation bandwidth of 4 GHz. This structure is simple in design with reduced size and provides slow-wave characteristics. This designed BPF is used for almost 2.5 GHz band around central frequency, almost no dispersion or scattering other than 0.5 ns group delay. Finally, the proposed structure has been fabricated and measured. There is a good agreement between the simulated and measured result. Therefore, the proposed filter is applicable in our modern microwave and millimetre wave communication systems due to its characteristics.