Direction finding using a switched parasitic antenna array

An electronically controlled antenna array consisting of one active element and a number of parasitic elements can be used for direction finding. Array directivity is controlled by exchanging the position of the feed and the parasitic elements. An array of four monopoles on a ground plane provides 360 degree azimuthal coverage with no moving parts, provides excellent directional resolution and can be controlled using a simple microcontroller. The antenna design, its application to direction finding and reliability in noisy environments are presented.