Cobwebb Antennas Applied on HF Communications

In order to build Timely and effective communication in HF blind-spot (20-100KM), Cobwebb folded dipole antenna was designed as well as matching circuitry. In this paper, antenna structure and antenna electric-height are simulated and amended in the use of electromagnetic simulation software FEKO. Antenna radiation patterns in the different electric-height are given. It is clear that the proper electrical antenna height from the ground is λ/4 in the simulation and actual test results and maximum gain is got in the direction of the vertical incidence (NVIS-Near Vertical Incidence Sky wave). The actual field test, Cobwebb antenna with the FT-450 HF radio work well in blind-spot, in addition to Cobwebb antenna does not require the land to build a complex network system, set up evacuation quickly, very suitable for tactical and strategic HF communications.