FRACTAL-SHAPED COMPLEMENTARY ELECTRIC-LC RESONATOR FOR BANDSTOP FILTER

An equivalent circuit model for single negative metama-terial (MTM) transmission line based on microstrip complementary electric inductive-capacitive resonator (CELC) is proposed for the first time. The verified circuit model gives strong support to the interpreta-tion of all exhibited electromagnetic (EM) phenomena. The nonpure magnetic and electric resonances have been demonstrated by consti-tutive EM parameters. Based on the conclusions that have drawn, a more compact sub-wavelength particle based on Hilbert-shaped CELC (H-CELC) is proposed. The design procedures of the H-CELC-loaded MTM cell are derived based on the circuit model. For application, a bandstop filter covering one of the ISM bands 5.2 GHz by cascading two H-CELC cells is designed, fabricated and measured. Consistent results between simulation and measurement have confirmed the de-sign. The established theory based on the proposed circuit model is of reference value for the design of novel bandstop devices.