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

A dual linearly polarized antenna array with end-fire radiation at the 60-GHz band is proposed by combining two types of magneto-electric dipoles (ME-dipole), which operate in vertical polarization (Vpol) and horizontal polarization (H-pol), respectively. Based on the substrate integrated waveguide (SIW) 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.