Compact Beam Steering Antenna With Low-Loss Co$_2$ Y-Type Hexagonal Ferrite Elements for Wireless Multiple-Input Multiple-Output (MIMO) Antenna Applications

A low-loss Co$_2$Y hexagonal ferrite (Ba
₂
Co
_1.9
Zn
_0.1
Fe
₁₂
O
₂₂
) has been developed for miniaturization and performance improvement of wireless multiple-input multiple-output (MIMO) antennas. The ferrite material has permittivity and permeability of 6.7 and 2.1, respectively, with dielectric loss tangent less than 0.007 and magnetic loss tangent less than 0.034 below 2.5 GHz. A beam steering antenna operating at 2.4 GHz band was designed and fabricated using the ferrite elements having a total volume of 18 mm × 18 mm × 100 mm, which has compact size, low loss, and good radiation characteristics. The antenna offers three modes with nine radiation beam patterns at the frequencies of 2.4 GHz band. The measured peak gain of all beam patterns ranges from 4.0 to 6.8 dBi.