Miniaturized Microstrip Lowpass Filter With Wide Stopband Using Suspended Layers and Defected Ground Structure (DGS)

In this paper, a novel compact wideband rejection LPF using defected ground structure (DGS) is presented. The proposed LPF consists of hi-lo etched slots in ground metallic plane as defected ground structure(DGS) and of microstrip hi-lo structure, which corresponding to capacitance and Inductance on the top layer. The effect of the DGS slot on the characteristics of the investigated filter is examined. In this work we have proposed a simple method to realize a compact DGS LPF with good characteristics . In order to prove the efficiency of the method, a comparison is made between the new DGS LPF and conventional filters , which shows that the proposed filter with etched cells is enough to obtain better performance by suppressing ripples and a very large stop band. Measured results are found to be in good agreement with the simulation results.