High-Gain Design of a Patch Antenna Using Stub-Loaded Artificial Magnetic Conductor

In this letter, a stub-loaded artificial magnetic conductor (SLAMC) structure is proposed as the ground plane of a probe-fed patch antenna. The novel cell is analyzed using the equivalent circuit, which reveals that the loaded stub would introduce an interdigital-like capacitance for perturbation of the surface current distribution. Simulated results show that the antenna placed on the proposed SLAMC plane can achieve a gain enhancement of 1.73 dB, wider bandwidth, and higher aperture efficiency than that placed on the square AMC plane. Moreover, the analysis of surface current density and electric field density indicates that the modified surface current on the SLAMC plane by the loaded stubs causes more uniform electric field on the radiation aperture and thus improves the gain and aperture efficiency. For demonstration, the proposed and reference antennas are fabricated and measured. Good agreement can be well observed between the simulated and measured results.