A dual circularly polarized (CP) omnidirectional antenna based on slot array in coaxial cylinder structure is presented in this paper. It is constructed by perpendicular slot pairs around and along the axis of the coaxial cylinder to realize the omnidirectional CP property. and two ports are assigned in its two sides as left hand circularly polarized (LHCP) port and right hand circula... https://www.roneverhart.com/Turbosound-TS-18SW700-8A-18-Low-Frequency-Loudspeaker-p31480/