A compact broadband antenna for ultra high frequency and L band on 5G new radio base stations

作者：Cui, Yuehui; Tu, Zhenxing; Qin, Yue; Li, RongLin^*

来源：IET Microwaves, Antennas and Propagation, 2023, 17(5): 361-368.

DOI：10.1049/mia2.12343

• broadband antennas
• dipole antennas

A simple method is proposed for the realisation of compact dual-polarised antennas. The aperture area of a dual-polarised dipole antenna can be reduced by half by surrounding the antenna with a square loop. Based on the method, a broadband compact dual-polarised antenna is developed. The broadband dual-polarised antenna consists of two +/- 45 degrees-polarised dipoles surrounded by a square loop and fed by two orthogonal broadband baluns. A resonance at a sfrequency (f(Lr) = 0.7 GHz) is created by the square loop, leading to a compact size of about lambda(Lr)/4 x lambda(Lr)/4, where lambda(Lr) is the wavelength in free space at f(Lr). Another resonance at a higher frequency (f(Hr) = 1.5 GHz) is generated by etching open slots on the +/- 45 degrees-polarised dipoles. A combination of the lower-frequency and the higher-frequency resonances results in a broadband operation. Simulation and experimental results show that the compact dual-polarised antenna achieves an impedance bandwidth of 75% (0.69-1.52 GHz) for return loss > 15 dB with stable radiation patterns, which is potential to be used for 5G new radio base-station applications.