Abstract
A low pass filter (LPF) using High-Low impedance line (Hi-Lo) interdigital Defected Ground Structure (DGS) with compact size and large stopband is presented in this paper. Both of the two characteristics are benefit from the introduction of the high impedance line in the conventional interdigital DGS, which can decrease the transmission zeros of the DGS without changing its overall size. To better explain the principle of the proposed DGS, the equivalent circuit is also built and extracted.