Bandpass Filter for 5. 8GHz Using Defected Ground Structure Based on UWB Antenna

Defected ground structures (DGS) have known to be providing improvement in characteristics of many microwave circuits. This bandpass filter is designed placing rectangular slot in the top plane and defected ground structure in the ground plane. DGS is used for property of miniaturizing the size of antenna and improving the mutual coupling between the resonators. The proposed dumbbell shaped DGS is used to tune the bandpass filter to 5. 8 GHz with dimension of $\pmb{40}\ \mathbf{mm}\times \pmb{15}\ \mathbf{mm}$ . The DGS unit of bandpass filter provides two transmission zeros near the passband edges. The filter gives an insertion loss of -1.8 dB” a return loss of -18.6 dB and -3dB bandwidth of 1.32 GHz.