Spatially Decoupled 8-Port MIMO Diversity Antenna for Point-to-Point Backhaul Wireless Applications

This study focused on a spatially decoupled 8-port MIMO antenna, strategically designed for point-to-point (PTP) backhaul wireless applications at designated 7-GHz frequency band. Utilizing a conventional dipole-driven-antenna-element (DDAE), the design asserts a polygonal interface to assemble 8-port MIMO configuration, avoiding additional isolation network. The initialization of DDAE study shows inductively dominant and capacitively coupled nature, which are primarily analyzed with modal synthesis on its resonance behavior and then extended to a sequential array configuration. This design topology self-annihilate the trapped coupled signals from antenna ports without affecting its intrinsic resonance mechanism, and hence, good port-isolation ($>$ 24 dB) is achieved. The radiation mechanism shows discrete pattern diversification with stable high peak gain of 8.02 dBi at designated ports. To rationalize its counterparts, a prototype antenna has been fabricated and experimented to operate from 6.5 to 7.6 GHz for dedicated 7-GHz PTP microwave backhaul RF wireless applications. The correlation coefficient between the antenna ports shows appreciable limits with ECC 0.2 viable for indoor, outdoor, and isotropic environments.