Electrically small antenna for maximising transmission into HF ground waves

A top-loaded, inductively-coupled, electrically small antenna is designed for HF ground wave transmission. A genetic algorithm is used to optimise the antenna parameters. Two prototype antennas have been built and the test results match well with simulations. Both antennas have an electrical size kr of 0.2, greater than 65% efficiency and transmission performance within 1 dB of a commercial whip.