Performance evaluation of HF aircraft antenna systems

Many antennas, especially for aircraft application, must radiate into large sectors and operate over wide bands of frequency. At the same time, means of pattern control are often limated. In order to evaluate the performance of such antennas, several antenna-rating schemes have been proposed in the past. This paper¹is concerned with the evaluation of HF aircraft antennas used for long-range voice ground-to-air and air-to-ground communications. The different antenna evaluation methods are compared theoretically for consistency among themselves. It is shown that they all lead to essentially identical relative ratings of different antennas used on the same aircraft. Furthermore, these ratings can be related to articulation scores, operationally the most significant parameter of voice-communication circuits. Since all the rating schemes investigated lead to about the same results, the simplest of these, namely the radiation pattern efficiency, appears to be the most suitable measure of effectiveness of HF aircraft antennas. The conclusions reached were verified through computations on radiation patterns obtained from model measurements.