The Effect of Coupling on Antenna Array Beamforming at Millimeter-Wave Frequencies

Millimeter-wave data links (at 28, 38 and 60 GHz) state as a key enabler for future communications. At these frequencies, the high propagation losses demand for the utilization of very directive antennas, which make techniques like adaptive beamforming play a big role. Among multiple existing beamforming algorithms, techniques like null steering beamforming provide with a very accurate placement of nulls and main lobe of the radiation pattern. However, these methods often remain efficient only under theoretical scenarios, in which the array is considered to be composed of uncoupled isotropic point sources. In this work, a study is conducted on the effect of antenna array coupling on the realistic performance of the null steering beamforming algorithm. Two different antenna arrays, a linear and a planar one, are designed and simulated, and the presence of mutual coupling is studied on both of them.