Compact lowpass filter with high and wide rejection in stopband using front coupled tapered CMRC

A front coupled tapered compact microstrip resonator cell is proposed. It consists of a microstrip transmission line with high impedance, two tapered with front coupled and two arms at two ends of the high impendence transmission line. The proposed filter has low insertion loss, high return loss in the passband and high and wide rejection in the stopband, as well as compact size. The demonstrated filter has been designed, fabricated and measured. Good agreements are obtained between its measured and simulated S-parameters.