A SCALABLE COMPACT WIDEBAND DUAL-POLARIZED PRINTED DIPOLE ANTENNA FOR BASE STATION APPLICATIONS

Abstract

A novel compact wideband dual-polarized printed dipole antenna for base station application is presented.The proposed antenna is composed of four assembled substrates.Two pairs of identical arrow-shaped conductive lines on the tophat substrate form two orthogonal polarized dipoles.Two baluns connected with 50 Ω coaxial cables are integrated on another two vertical substrates to excite the dipoles.The other horizontal board at bottom provides grounding.A rectangular boxshaped reflector is also used to enhance its stability in radiation patterns over the operating frequencies.It achieves 22% size reduction from the conventional printed half-wavelength cross-dipole, and 43.2% impedance bandwidth (VSWR < 2), while maintaining a stable radiation pattern with measured Cross-Polarization Degradation (XPD) better than -22 dB at boresight and an average peak gain of 8.4 dBi for a 65 • Azimuth Beamwidth base station application at 700/800/900 MHz bands.With the scalable miniature structure, it may also find itself suitable for side-by-side multiband Multi-Input Multi-Output (MIMO) or Large-Scale Antenna (LSA) 5G base station applications.A 4 × 4 array prototype of the LSA is also designed and fabricated, and it achieves 27.8% impedance bandwidth (VSWR < 1.5) with well decorrelated element performance and array XPD better than -20 dB across as large as 30 • tilting range.