Theoretical and experimental study for long-distance lower frequency skywaves of the HF band

By analyzing the propagation characteristic of lower frequencies of the HF skywaves, we found that the radiation angle is smaller and in middle and high magnetic latitudes the vertical polarization component is more larger on lower frequencies of the HF band. The conclusions above were verified by two experiments. Furthermore, the experiment results also verify the validity of the vertical fishbone antenna for receiving long-distance signals because of its lower radiation angle of elevation. The conclusions of the experimental study for long-distance lower frequency skywaves of the HF band are highly significant for efficiently receiving HF full band signals.