Design of Half-Ring MIMO Antenna to Reduce the Mutual Coupling

Abstract

We propose a novel, dual-polarized MIMO radiator, which consists of half rings, and included in the ring a square shape at the top side and half circular shape at bottom side operating from 2 to 10 GHz with a microstrip feeding. The suppression of mutual coupling is obtained by maintaining the separation between the patches around 0.25 λ₀. The half-ring MIMO antenna is resonating at dual band of frequencies at 7.24 and 8.16 GHz with impedance bandwidths of 430 and 230 MHz, has |S₁₁| < −10 dB in the MIMO range from 2.0 to 10.0 GHz and has a mutual coupling with |S₂₁| < −20 dB. The radiator has a low ECC (envelope correlation coefficient) with values equal to approximately less than 0.025, which will prove that the half-ring MIMO radiator shows better diversity performance. The half-ring MIMO radiator has improved the parameters of reflection coefficient, mutual coupling, realized gain, group delay and real/imaginary impedances.