The effects of antennas on HF propagation level

The transmitting antenna for HF communication links is generally simple with a vertical or horizontal polarization. The receiving antenna provides signals corresponding to different paths or modes( O and X). To interpret HF communication attenuation, fading is computed using a statistical method and the classical antenna field pattern. Such a radiation pattern is inadequate in the case of HF propagation as wave polarisation in the ionosphere is rarely linear. A new approach to the analysis of the effects of antennas is proposed.