Design of Radio Frequency Direction Finder for Automotive Applications

A feasible and robust small-aperture radio frequency passive direction finder is presented that is predestined to be used in multipath environments. The hardware part was implemented as a 2-channel interferometer with data acquisition circuitry. The angle of arrival information is extracted deploying parallelogram envelope constellation algorithm (known also as the histograms method), which is based on a constellation formation in the monopulse plane over a short time duration. Additionally, the algorithm processing stage is further refined to combat multipath reflections. Simulated and measured data demonstrate the capability and benefits of the designed system