Direction finding (DF) is a term used to describe the process of locating, tracking and distinguishing various sources of radio transmissions. DF is a well-established technology, and has become increasingly popular in military and commercial communications.

DF systems calculate the direction of arrival of a particular radio signal using an array of spatially displaced antennas or rotating antenna. Nearly all DF algorithms require that signals from multiple antennas are received and routed to multiple processors or DSPs. These processors or DSPs are then used to compare the phase and arrival time from the various signals to derive the location, speed and direction of the signal source. This application note describes how Spectrum helped one particular customer to develop a high performance DF system.