A Twelve-Ports Dual-Polarized MIMO Log-Periodic Dipole Array Antenna for UWB Applications

Abstract

A twelve-port dual-polarized multiple-input–multiple-output (MIMO) log-periodic dipole array (LPDA) antenna for ultra-wideband (UWB) applications is proposed in this paper. In the MIMO antenna, there are 12 antennas, six for horizontal polarization and six for vertical polarization. In order to achieve dual linear polarizations and beam switching, six horizontal antennas are placed in a sequential, rotating arrangement on a horizontal substrate panel with an equal inclination angle of 60 to form a symmetrical structure, while the other six antennas for vertical polarization are inserted through slots made on the horizontal substrate panel. In addition, all twelve antennas share a hexagon common ground on the back of substrate and feed by micro-strip line. A prototype of the MIMO antenna is manufactured and the reflection coefficients, coupling isolation, radiation pattern and peak gain are measured. The MIMO performance of the MIMO LPDA antenna is predicted and evaluated by envelope correlation coefficient (ECC) and total active reflection coefficient (TARC).