A 5G Millimeter-Wave Circularly Polarized Planar Antenna Array

This paper investigates a left-hand circularly polarized (CP) magneto-electric (ME) dipole antenna array at millimeter-wave (mm-wave) 5G band. In the element, the circular polarization radiation is realized by connecting the inner corners of one pair of the ME dipoles and cutting the corners of the other pair of the ME dipoles. To verify the design, a 2 × 2 array antenna is designed, fabricated and measured. The measured fractional bandwidth (FBW) is 27.6% (25-33 GHz) for |S 11 | < -10 dB, and the 3-dB axial ratio (AR) bandwidth is 20.7% (26-32 GHz). In addition, the measured peak gain is 14.03 dBic at 29 GHz and the peak radiation efficiency is around 92.88%.