A compact coplanar waveguide dual-band bandpass filters based on defected ground structures

Abstract

A dual-band bandpass filter using coplanar waveguide (CPW) has been proposed in the paper. To generate the first passband, a gap is adopted in the central strip of the CPW main transmission line, and two pairs of spiral-shaped defected ground structures (DGSs) are added to the ground planes. Then, the loaded four L-shaped slots in the central strip of the CPW main transmission line can achieve the second passband. The measured central frequencies of the dual-band bandpass filter are 3.59 GHz and 5.87 GHz. The proposed filter has good dual-passband performance and good stopband suppression. key words: dual-band bandpass filter, coplanar waveguide, defected ground structures Classification: Microwave and millimeter-wave devices, circuits, and modules