Design of an HF Transmitter Antenna for Bistatic Ionospheric Soundings in Antarctica

This paper presents the design of a suitable high frequency (HF) transmitter antenna for installation at the South Pole as part of a low-powered bistatic ionospheric sounding system intended to detect traveling ionospheric disturbances (TIDs). A highly directional antenna was required so as to reduce interference with a nearby South Pole SuperDARN radar. HF ionospheric propagation was investigated, with the polar ionosphere and its impact on system functionality being of particular concern. Freely available propagation prediction tools were reviewed and ICEPAC was selected for use based on its high- latitude capabilities. Manual calculations of the non-deviative radio wave absorption in the lower layers of the ionosphere were done (for both extraordinary and ordinary wave modes) by using the magnetoionic Appleton-Hartree equations in conjunction with relevant ionospheric and geophysical models. These results were used to supplement transmission losses estimated with ICEPAC so as to ensure that enough power is supplied to allow for both wave modes to reach the receiver. The properties of the lossy ground at the South Pole were researched and a multi-layered substrate ground plane was modeled for use in FEKO simulations. Several antennas were investigated through an iterative design process and a three element rectangular loop Yagi-Uda was chosen for final consideration.