A compact microstrip lowpass filter based on defected ground structure

摘要

A new compact defected ground structure (DGS) is proposed for the microstrip line. The performance of the new DGS is analyzed. Here this DGS is used to design a compact lowpass filter (LPF). The fabricated filter has a 3 dB cutoff frequency at 2.4 GHz and it is as small as 22.3 mm × 16 mm. Suppression levels, for the fabricated filter, are greater than 20 dB from 3 to 10.3 GHz. The insertion loss in the passband is less than 0.6 dB from DC to 2 GHz. The design of the filter is simple and it shows good frequency response.