A Dual Linearly Polarized End-Fire Antenna Array for the 5G Applications

A dual linearly polarized antenna array with end-fire radiation of the 60-GHz band is proposed by combining two types of magneto-electric dipoles (ME-dipole), which operate in vertical polarization (V-pol) and horizontal polarization (H-pol), respectively. Based on the substrate integrated waveguide structure, two kinds of ME-dipole are placed closely by sharing the same metallic post wall between them, achieving an element space of 0.77λ0. Besides, mutual coupling between the close elements is numerically analyzed and then suppressed by making modifications to the antenna structure. The proposed dual-polarized element achieves bandwidths of 26% and 32% (|S11| <; -14 dB) for the V-pol and H-pol, respectively. A 1×8 element array is designed, fabricated, and measured. Good agreement is achieved between the measurement and simulation. For the V-pol excitation, a bandwidth of 21% is obtained and gain is up to 16.1 dB. For the H-pol excitation, the bandwidth is 18% and peak gain is 15.1 dB. Radiation patterns are stable over the operating frequencies with cross polarizations below -30 dB for both polarizations. The port isolation is very high above 45 dB. With all these advantages of dual polarization, end-fire radiation, stable gain, and high port isolation, the proposed array is a potential candidate for the future 5G applications.