Investigations on Dual Slant Polarized Cavity-Backed Massive MIMO Antenna Panel With Beamforming

A cavity-backed dual slant polarized and low mutual coupling antenna array panel with frequency band from 4.9 to 6 GHz is analyzed and realized for the MIMO antenna 5G applications. The beamforming capability of this array is also explored. The printed cross dipoles fed with balun and enclosed in a cavity are used as radiating elements. The two cross dipoles are placed at an angle of 45° and 135° giving slant polarizations. A 4 × 4 subarray of dimension 2.8λ × 2.8λ × 0.26λ where λ is free space wavelength at 6 GHz is designed, fabricated, and experimentally verified. It shows good impedance matching, port isolation, envelope correlation coefficient, and radiation characteristics which are desired for MIMO applications. Beamforming capability in the digital domain is verified using the Keysight SystemVue simulation tool for both 4 × 4 and 16 ×16 panel arrays which employ measured 3-D embedded element radiation pattern data of the fabricated 4 × 4 subarray. Four simultaneous beams using digital beamforming approach are also presented for the 16 × 16 array for multiuser environment base station antenna applications.