Diseño y construcción de la etapa de RF de un modem de banda ancha para HF

Abstract

Broadband HF modems are very important today for long distance communications, as most of new modulations tend to spread its resulting bandwidth above the HF channel frequency coherence bandwidth. This paper describes the design and construction of the RF front-end of a broadband (1 MHz) HF modem that will be an excellent tool for diversity analysis, propagation studies, etc. Design and block diagram are explained, and also some measurements and photographies are presented. Conclusions are drawn from the final prototype.