Ionosphere-induced cross polarization of circularly polarized UHF propagation

To explore the possibility of more efficient spectrum use in the UHF satellite communication band, ionosphere-induced cross polarization of circularly polarized waves was investigated. The Poincare sphere is used to obtain a simple closed-form expression of cross polarization for propagation at an arbitrary angle with respect to the geomagnetic field. The predicted maximum cross polarization at 250 MHz is -25 dB.>