Bandwidth enhancement of a patch antenna by loading complementary K-shaped artificial magnetic conductors in ground plane

In this paper, the ground plane of a microstrip patch antenna is loaded with periodic array of complementary K-shaped metamaterial structure designed to behave as an artificial magnetic conductor (AMC). Unit cell of K-shaped AMC is designed to provide in-phase reflection at 2.4 GHz. A microstrip patch antenna is designed to resonate at 2.4 GHz in the band 2.386-2.414 GHz with 1.17% impedance bandwidth and peak gain of 7.94 dB. The effect of loading the ground plane of antenna with repetitive complementary K-shaped AMCs on antenna characteristics such as gain, bandwidth and radiation efficiency is studied. On loading complementary K-shaped AMCs in antenna ground plane, antenna resonates at 2.4 GHz in the band 2.379-2.436 GHz with 2.38% impedance bandwidth and peak gain of 6.37 dB. Both K-shaped AMC unit cell and antenna are designed and simulated by using finite element method based electromagnetic solver - Ansys HFSS. Compared to the antenna without K-shaped AMC loaded ground, the antenna with K-shaped loaded ground achieved wider bandwidth and better radiation efficiency.