Harmonic suppression using optimised hexagonal defected ground structure by genetic algorithm

摘要

This study analyses the effects caused by a new hexagonal defect ground-plane (DGS) structure when it is applied to a rectangular microstrip antenna and studies its effectiveness to suppress higher-order modes. To improve the rejection characteristics of the analysed DGS, a genetic algorithm was used to optimise its parameters. Controlling higher-order modes of the fundamental operating frequency was successfully demonstrated, and the experimental results showed that optimising the hexagonal DGS could enhance thenSn₁₁nparameter of the fundamental mode while simultaneously suppressing or further attenuating higher-order modes. Such results are particularly important once DGS is applied for self-immunity of antennas against harmonic radiations by avoiding the use of a filter circuit.