A ferrite single annular-ring microstrip antenna with two feed probes was proposed and simulation results were presented. Simulated S-parameters show that a better separation between the feed probed must be achieved.
Manufactured ferrite 1-CPA and ferrite 1-ARA were characterized by S-parameter measurements and radiation patterns. Permeability, permittivity, and associated loss tangent values of manufactured substrate material deviated from the parameters used for FEKO simulations.
Thus, expected Sparameters and radiation patterns were not achieved. But FEKO simulations using measured permeability, permittivity, and loss tangent values agree with measurements, thus showing that if the substrate parameters were exactly the same as those used for initial simulations, then measurement results would show expected values.