Efficient Isolation between Electrically Small Metamaterial-Inspired Monopole Antennas

In this paper, a new electrically small metamaterial-inspired monopole antenna is presented. It consists of a simple square-shaped coplanar waveguide (CPW-fed) monopole with an embedded complementary split ring resonator (CSRR). It operates at three distinct frequency ranges around 2.45, 4.2, and 5.8GHz, with low return loss and uniform radiation patterns, making it a perfect candidate for modern wireless applications. Furthermore, using this as a primary unit to construct two different 2×2 MIMO configurations, we achieve systematic minimization of mutual coupling, using additional single negative (SNG) metamaterial-inspired resonators. Mutual coupling is reduced by as much as 27 dB at the frequency of interest. Simulated and measured results of all antennas are in good agreement.