EM isolation enhancement based on metamaterial concept in antenna array system to support full-duplex application

This paper proposes EM mechanism to improve the isolation between transmitting and receiving array antennas using metamaterial EM band gap (MTM-EBG). The proposed mechanism can be applied to full-duplex array antenna system with very closely spaced arrays (0.33λ
₀
) with no degradation in radiation pattern. Using the proposed technique the isolation is shown to improve by >30 dB in an antenna array consisting of three-element microstrip patches designed to operate across 9.7 to 12.3 GHz. Parametric analysis was used to optimise the decoupling arrays performances. The proposed antenna array has physical dimensions of 65×22.5×1.6 mm
³
and an electrical size of 2.16λ
₀
×0.75λ
₀
×0.053λ
₀
, where λ
₀
is free space-wavelength at mid-band of 10 GHz.