Antenna for a Ground Based HF-beacon for Propagation Studies

Background:
The Super Dual Auroral Radar Network (SuperDARN) radar is part of an international network of 35 radars distributed over the northern and southern polar regions. SuperDARN is a High Frequency (HF) Skywave radar used to study the ionosphere and other space weather related phenomena. SuperDARN is used and operated by the South African National Space Agency (SANSA).
SANSA’s SuperDARN radar comprises of a fully reconfigurable, digit platform consisting of 20 transceiver boxes each with full transmit and receive functionality and controlled by a custom FPGA board (Tiger-3). The radar uses a 16-element Twin Terminated Folded Dipole (TTFD) phased array and a 4-element secondary array to transmit and receive 300us/100us pulses at up to 2.4 kW per antenna over a frequency range between 8 MHz and 20 MHz. Each antenna gets its own transceiver box and the timing is controlled via a dedicated timing node, which distributes a common clock signal to all 20 transceivers via fast Ethernet cables.

This project:
SANSA has developed a ground based HF beacon, which will be installed near the South Pole. This beacon, which transmits CW and/or Morse Code at 12.5MHz, requires a directional antenna to transmit the signal across the Antarctic continent to SANSA’s HF Radar, where it will be received. This signal will be used for propagation studies and for identifying gravity waves. The South Pole station has its own SuperDARN radar, so the antenna is required to have a very low directivity in the direction of the SP Radar array.