A novel lowpass filter with ultra-wide stopband and improved q-factor performance using H-Defected Ground Structure (DGS)

In this paper, a novel compact wideband high-rejection LPF using H-defected ground structure(DGS) is presented The effect of the DGS H-slot on the Q factor characteristics is examined. Comparison between the new DGS LPF and conventional filters shows that the proposed filter with its simple geometric structure including only two H-cells guarantees a suppressed ripples passband and a very large section of a stopband From 2.5 to 16 GHz, the investigated DGS-LPF has a rejection level better than 20 dB. Measured results show good consistency with calculations.