Abstract: An apparatus performs dual circular polarization in a flat plate antenna simultaneously, and does not require more than two meander line polarization layers. A first linear polarization layer and a second linear polarization layer including a polarization power divider (2, 4) and a radiation panel (3, 5) positioned on the polarization power divider (2, 4), are provided to respectively perform first and second senses of linear polarization. Additionally, a first meander line polarizer layer (6) is positioned on the second linear polarization layer and a second meander line polarizer layer (7) is positioned on the first meander line polarizer layer. The first and second meander line polarizer layers (6, 7) convert linear polarization signals into a circular polarization signals.