Chapter 1 - Wireless Direction-Finding Fundamentals

Abstract

Wireless direction finding has a long and distinguished history going back to the very beginnings of wireless communications around the turn of the twentieth century. Many advances have been made in the field of direction finding since the early 1900s, for the most part due to advances in technology rather than new concepts or principles. The remarkable developments in electronics and in devices and components for generating and amplifying signals at higher and higher frequencies have greatly extended the capabilities and applicability of direction-finding systems. The shift from analog to digital technology has increased tremendously the flexibility of such systems and their ability to monitor and keep track of signals over a wide range of frequencies and large geographical areas. However, the basic direction-finding techniques have not changed much, with the exception of the introduction of “super-resolution” algorithms for multiple co-channel signals.