Design of compact seven poles low pass filter using defected ground structure

This paper presents a simple technique to design the seven poles low pass filter using defected ground structure (DGS) having better than -20 dB rejection up to 8fc. The proposed low pass filter (LPF) does not have any, discontinuity elements and the repeated high low impedance lines, which are essential for design of conventional LPF. Only DGS patterns and one capacitive transmission line used for the design of the proposed LPF filter. The proposed design gives simple structure, and small size (42.3% of a conventional LPF). This filter is fabricated on FR-4 substrate, and its measured results are shown to be in good agreement with the simulated.