Modelling complementary-split-rings-resonator (CSRR) left-handed lines with inter-resonator´s coupling

A circuit model for the accurate description of left handed microstrip lines based on complementary split ring resonators (CSRRs) is proposed in this work. The main relevant contribution is the inclusion of inter-resonator´s coupling in the model. From the analysis of several structures, where the shape and distance between adjacent CSRRs differs, it is concluded that electric coupling between CSRRs can be significant if these resonators are rectangular and they are tiny spaced. For circular-shape CSRRs, coupling can be neglected regardless of the distance between resonators. Several prototype devices have been fabricated and measured in order to validate the model and the previous conclusions. The proposed analysis is of interest for the design of planar microwave circuits based on CSRR left handed lines