Miniaturization and isolation improvement of a multiple‐patch antenna system using electromagnetic bandgap structures

In this article, a compact multielement antenna system composing of microstrip patch antennas is designed by using electromagnetic bandgap (EBG) structures. Two distinct EBG structures are designed to achieve the two objectives of miniaturization and suppression of interelement coupling due to surface waves in a multiantenna system. By embedding an EBG array operating in the slow‐wave region, the area of the microstrip patch antenna is reduced by 67.48%. To alleviate the resulting increased back radiation, a second EBG structure is designed to surround the miniaturized patch antenna and close to 8 dB improvement in the front‐to‐back lobe ratio is achieved. As well, the second EBG design is included in a 2 × 2 multiantenna system to suppress interelement coupling. It is found that the coupling is reduced significantly when utilizing the proposed EBG rings.