A compact parallel coupled wideband bandpass filter with DGS and spurline

A simple compact wideband coupled line bandpass filter using defected ground structure (DGS) and spurline is presented here. The proposed filter has a fractional bandwidth of 35% at central frequency 5 GHz. The conventional coupled line bandpass filter is miniaturized with the implementation of DGS in the proposed method. Return loss better than 20 dB and 3 dB bandwidth of 1.77 GHz is achieved. The spurline is incorporated in the microstrip feed line to suppress the higher order harmonics.