Ahmed Siddig Ibrahim Mustafa¹, Mohammed Almoiz Abd-Almoniem Mohammed¹, Nassrin Ibrahim Mohamed Elamin^1,

An electronically controlled parasitic antenna array consisting of one active element connected to a software defined radio (SDR) receiver and four passive parasitic elements used to design and construct affordable radio direction finding system. The directivity of the antenna array achieved by increasing/degreasing the electrical length of the parasitic elements. The design based on a central active monopole and an array of four parasitic monopoles equidistantly from the central element by 0.20 λ, placed on ground plane to provide the 360 degree azimuthal coverage without any moving parts, provides excellent directional resolution. The system is controlled by using Arduino to switch between regions (0-90),(90-180),(180-270) or (270-360) and analysed by using a newly developed method based on I/Q samples to extract the amplitude and phase of the desired signal to find the exact direction in that region. The antenna design, its application to determine the direction finding, the new algorithm are presented below.

RDF, AoA, parasitic monopoles