What is circular polarization?

This polarization can be visualized by a signal propagating from an antenna that is rotating.  The tip of the electric field vector will trace out a corkscrew as it propagates.  A right hand circularly polarized rotates in a right hand fashion, whereas, a left hand circularly polarized antenna in a left hand fashion.  In this configuration, it should be noted that the input power to the antenna is split equally between the polarization components taking a 3dB reduction in signal strength.