On the advantages of loop-based unit-cell's metallization regarding the angular stability of artificial magnetic conductors

The angular stability of artificial magnetic conductors (AMCs) with hexagonal-shaped and square-shaped, patch-based and loop-based unit-cell's metallization is studied for comparison. The influence of the gap distance between the unit-cells' metallization on the overall AMC angular stability, while maintaining the resonance frequency and meeting the specified bandwidth requirements for a given dielectric substrate, is shown for the first-time. This observed phenomenon is explained by means of a simplified equivalent circuit devised for the unit-cells under study. Experimental characterization regarding AMC's operation bandwidth and angular stability is carried out in an anechoic chamber for an AMC with hexagonal-shaped loop-based unit-cells, since from simulation results it outperforms the other AMCs under study.