A Wideband Circularly Polarized Magneto-Electric Dipole Antenna Array for Millimeter-Wave Applications

A wideband circularly polarized (CP) magneto-electric (ME) dipole antenna is presented in this communication. The uniqueness of this design stands from the fact that the electric dipoles are 3-D-meandered and shorted to the ground plane at the edges of patches, respectively. By this means, two orthogonal ME-dipole modes with similar magnitudes and phase quadrature are well excited. Thus, a wideband CP ME-dipole antenna is achieved. Simulation results indicate that the antenna element achieves a wide impedance bandwidth of 49.6% (24.7–41 GHz) and a 3 dB axial ratio (AR) bandwidth of 50.4% (26.7–44.7 GHz) with a peak gain of 8 dBic. For proof-of-concept demonstration, a 4 $\times $ 4 CP ME-dipole antenna array is investigated, implemented, and measured. The measurement results of the antenna array show a wide impedance bandwidth of 50% (24.5–40.8 GHz) and a 3 dB AR bandwidth of 44% (27.5–43 GHz) with a maximum gain of 19.2 dBic. The proposed CP antenna array demonstrates distinctive properties, such as broad impedance and AR bandwidth, stable gain, symmetrical radiation patterns, and ease of integration.