High-efficiency microstrip patch antennas using non-periodic artificial magnetic conductor structure

A novel artificial ground composed by several non-periodic rectangle artificial magnetic conductor (RAMC) structures is firstly proposed, and employed as the ground plane of a probe-fed patch antenna. Based on the design strategy of parasitic patches, the dimensions and arrangements of these RAMC cells in the artificial ground as well as the size of the ground plane are investigated and discussed. As results, two RAMC-based antennas with high efficiency are proposed, which respectively can achieve very high efficiency of over 90% and stable efficiency of over 80% within the operating frequency band. For demonstration, two proposed antennas are fabricated and measured. Good agreement can be observed between the simulated and measured results.