Real Time Four Channel Phase Comparison Direction Finding Method

In this paper, the implementation of real time direction finding method on FPGA platform for the direction finding systems that have four coherent channels and linear antenna array is presented. If the signals that are received from same direction and distance between antennas are processed by a FPGA card, different antenna pair combinations can be generated. Direction finding is achieved by the comparison of possible angle of arrival values that is calculated using measured fundamental phase and overlapping replicas. The developed real time algorithm and implemented structure on FGPA platform, which includes phase difference calculation, overlapped phase differences and angle calculation blocks, finally ambiguity resolution method and direction finding results are presented.