Sharp Response Microstrip LPF using Folded Stepped Impedance Open Stubs

Abstract

A novel microstrip lowpass filter with high selectivity and wide stopband is proposed that comprises two lateral folded open stubs and a central mirrored semi-circle ended suppressing cell. The proposed filter has cut-off frequency of 2.28 GHz and is very compact. The stopband width with attenuation level more than -20 dB is equal to 5.47 f_c and the transition band is only 0.14 GHz. This filter is designed, fabricated and measured and the simulated and measured results are in good agreement

Keywords

• Low pass filter
• microstrip technology
• folded open stub
• sharp response
• wide stopband