Non-Periodic Fractal-Shape Defected Ground Structure for Low-Pass Filter

A novel non-periodic defected ground structure(DGS) for low-pass filter using Koch fractal are proposed.Simulation shows that it is different from the periodic DGS in that the non-periodic unit lattices of new DGS can have obtained passband and enlarged stopband bandwidth.The designed non-periodic fractal-shape DGS of LPF is processed and measured to verify its validity.Results show that the maximal return loss sidelobe level is-24 dB and that the stopband width is 6 GHz.