Compact reconfigurable defected ground structure (DGS) based multiband bandpass filters on Coplanar Waveguide technology

This paper addresses DGS based inductively coupled bandpass filters fabricated on Coplanar Waveguide (CPW) technology. The addition of the DGS to the conventional inductively coupled resonator BPF allows the miniaturization of the resonator by exploiting the transversal dimensions of the CPW, while maintaining its performance with respect to insertion and return loss values. On the other hand, the DGS cell allows reconfiguration of the structure from a single band to a multiband BPF. The design procedure of the filters with the DGS is explained with filters designed at 5 GHz. Simulated and measured results show good agreement.