  This paper proposes a beamforming design for millimeter-wave (mmWave)
backhaul systems with dual-polarization antennas in uniform planar arrays
(UPAs). The proposed design method optimizes a beamformer to mimic an ideal
beam pattern, which has flat gain across its coverage, under the dominance of
the line-of-sight (LOS) component in mmWave systems. The dual-polarization
antenna structure is considered as constraints of the optimization. Simulation
results verify that the resulting beamformer has uniform beam pattern and high
minimum gain in the covering region.
