Introduction to HF: Modulation and Propagation

This presentation covers two important aspects of HF (high frequency) communications: the modulation types most commonly used for HF communications and the fundamentals of HF propagation.

Modulation types include both double-sideband AM and single-sideband as well as narrowband FM. For digital modes, the use of amplitude shift keying (ASK) and frequency shift keying (FSK) are also discussed.

The propagation starts with a general introduction to HF and the main HF propagation modes (direct wave / line of sight, ground or surface wave, and skywave). Since skywave is the most unique and widely used HF propagation mode, in-depth discussions about ionosphere will be presented.

The presentation concludes with a short summary and a question and answer session.
This webinar is generously sponsored by Twin Cities IEEE MTT-S Chapter.