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 stop- band width with attenuation level more than -20 dB is equal to 5.47 fc 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.
