A Scalable Compact Wideband Dual-Polarized Printed Dipole Antenna for Base Station Applications

Abstract

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 CrossPolarization 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.