Computational models for bandwidth enhancement of electromagnetic bandgap (EBG) resonator antennas and their limitations

Since the pioneering work of Von Trentini in 1956, significant improvements in the performance of electromagnetic band gap resonator antennas (ERA) have been made. The focus of this paper is on the computational models and computational efficiency related to the enhancement of 3-dB directivity bandwidth of such antennas. We explore to what extent the two unit-cell numerical electromagnetic models, Superstructure Model and Defect-Cavity Model, can be efficiently used to reduce the computation burden of the design process to achieve the best antenna bandwidth. It was found that they are very useful for antennas with medium or large superstructure areas but for smaller antennas that have much wider bandwidths numerical analysis of the whole antenna is required to achieve the best directivity bandwidth.