A Compact microstrip LPF with aWide Stopband Using Modified T-shaped resonator

A microstrip lowpass filter (LPF) based on a T-shaped resonator is proposed in this paper. The proposed LPF has a simple structure. In this structure a high impedance transmission line is loaded by a modifiedT-shaped resonator and two tapered suppressing cell, which resulted in wide stopband. the proposed LPFsuppresses the 2nd to 4th harmonics with high attenuation level. The -3 dB cut off frequency of filter is 2.53 GHz.The proposed LPF presents wide stopband from 3.2 GHz to 10.34 GHz with attenuation level higher than -20 dB. The size of the proposed LPF is only 0.142λg × 0.214λg, which shows excellent size reduction