Four-Port CSRR-Loaded Dual-Band Dual-Mode Patch Sub-Array for Massive MIMO Applications

In this paper, we propose a four-port sub-array of dual-band dual-mode square patches loaded with complementary split-ring resonators (CSRRs), for application in massive MIMO base-stations. The CSRR loading induces an additional lower frequency radiation mode with orthogonal current distribution with respect to the fundamental mode. Full wave simulation results further validate the achieved high-gain (> 5.5 dBi) broadside pattern in both the bands, as well as the pattern/polarization diversity achieved via rotationally symmetric patch-arrangement.