An approach for improving the transition-band characteristic of a stepped-impedance low-pass filter

In this paper, an approach for improving the transition-band characteristic of a microstrip stepped-impedance low pass filter (LPF) is proposed. By loading stepped impedance resonators (SIRs) on the feed line of the LPF to form attenuation poles near the cut-off frequency, a sharp cutoff has been therefore obtained. Experimental data are in good agreement with the simulated results and then verified the idea.