Wideband Uniplanar Artificial Magnetic Conductors Based on Curved Coupled Microstrip Line Resonators

Novel broadband artificial magnetic conductor (AMC) structures based on curved coupled microstrip line resonators are presented. The characteristic feature of the proposed resonators is their relatively wideband resonance. Coupled microstrip lines composed of single-, double-, and multiple-loop AMC unit cells are proposed. The effects of the structure parameters on the fractional bandwidth are studied. Among the proposed structures, the multiple-loop geometry, which fills more space on the top layer of the planar (microstrip) AMC, demonstrates the largest bandwidth. The designed structure exhibits polarization angle independence, and it is also stable under small angular incident angle.