The influence of the method of excitation of a near ground four-arm spiral HF band antenna on its characteristics

Abstract. Four-arm spiral antennas with internal excitation are common and are part of many radio communication, navigation and location systems (including the HF band). There are known objections in the design of these antennas, which complicate their operation and lead to a decrease in efficiency, associated with the choice of the method of excitation of radiators. The aim of the article is investigation of the influence of the method of excitation of a near ground four-arm spiral HF band antenna on its characteristics (both separate and as part of other antenna-feeder devices) and formulating recommendations for simplifying operation and increasing efficiency. In article four methods of excitation of a near ground four-arm antenna were analyzed, considered as part of an antenna system consisting of an aperiodic antenna and a termination load for its radiators in the form of a near ground four-arm spiral antenna. The influence of the method of excitation of both the antenna system as a whole and a separately near ground four-arm spiral antenna on their characteristics has been studied. The analysis of the methods of excitation of a near ground four-arm spiral HF band antenna presented in the article and the recommendations formulated for the development of HF band antenna-feeder devices allow us to design and upgrade both near ground and aperiodic antennas of radio centers with increased efficiency and simplify their operation.