Vertical Array of Orthogonal Circular Polarised Quadrifilar Helix Antenna for Satellite MIMO System

Abstract

Orthogonal circular polarization based MIMO technique has been proposed to be integrated with land mobile satellite system to further increase its link capacity. Therefore, there is a need to the antenna at the transmitter and receiver to be able to radiate in both circular polarization (right hand and left hand) simultaneously. This paper proposes a vertical array of dual circularly polarized folded meandered printed quadrifilar helix antenna to be used at the mobile terminal of the system. By element folding and meandering, the axial length of the antenna can be reduced by up to 63.3%. The simulated and measured results of the antenna array show that the antenna has good return loss at the desired frequency of 2.4 GHz, low mutual coupling with value less than −20 dB and good cross polar discrimination at the main beam direction.